diff --git a/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.spec.ts b/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.spec.ts
index a818c752b..b57a83355 100644
--- a/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.spec.ts
+++ b/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.spec.ts
@@ -4,7 +4,7 @@ import { ComponentFixture, TestBed } from '@angular/core/testing'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import { NgbActiveModal, NgbModule } from '@ng-bootstrap/ng-bootstrap'
 import { NgSelectModule } from '@ng-select/ng-select'
-import { of } from 'rxjs'
+import { of, throwError } from 'rxjs'
 import {
   MailAction,
   MailMetadataCorrespondentOption,
@@ -15,6 +15,7 @@ import { CorrespondentService } from 'src/app/services/rest/correspondent.servic
 import { DocumentTypeService } from 'src/app/services/rest/document-type.service'
 import { MailAccountService } from 'src/app/services/rest/mail-account.service'
 import { SettingsService } from 'src/app/services/settings.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { CheckComponent } from '../../input/check/check.component'
 import { NumberComponent } from '../../input/number/number.component'
 import { PermissionsFormComponent } from '../../input/permissions/permissions-form/permissions-form.component'
@@ -81,6 +82,41 @@ describe('MailRuleEditDialogComponent', () => {
     fixture.detectChanges()
   })
 
+  it('should use empty related object lists when retrieval fails', () => {
+    const failed = () => throwError(() => new Error('Forbidden'))
+    const toastSpy = jest.spyOn(TestBed.inject(ToastService), 'showError')
+    jest
+      .spyOn(TestBed.inject(MailAccountService), 'listAll')
+      .mockReturnValue(failed())
+    jest
+      .spyOn(TestBed.inject(CorrespondentService), 'listAll')
+      .mockReturnValue(failed())
+    jest
+      .spyOn(TestBed.inject(DocumentTypeService), 'listAll')
+      .mockReturnValue(failed())
+
+    const failedFixture = TestBed.createComponent(MailRuleEditDialogComponent)
+    const failedComponent = failedFixture.componentInstance
+
+    expect(failedComponent.accounts()).toEqual([])
+    expect(failedComponent.correspondents()).toEqual([])
+    expect(failedComponent.documentTypes()).toEqual([])
+    expect(() => failedFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledTimes(3)
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving mail accounts',
+      expect.any(Error)
+    )
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving correspondents',
+      expect.any(Error)
+    )
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving document types',
+      expect.any(Error)
+    )
+  })
+
   it('should support create and edit modes', () => {
     component.dialogMode.set(EditDialogMode.CREATE)
     const createTitleSpy = jest.spyOn(component, 'getCreateTitle')
diff --git a/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.ts b/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.ts
index a123c097c..7731324c4 100644
--- a/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.ts
+++ b/src-ui/src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.ts
@@ -6,7 +6,7 @@ import {
   FormsModule,
   ReactiveFormsModule,
 } from '@angular/forms'
-import { map } from 'rxjs'
+import { catchError, map, of } from 'rxjs'
 import { EditDialogComponent } from 'src/app/components/common/edit-dialog/edit-dialog.component'
 import { Correspondent } from 'src/app/data/correspondent'
 import { DocumentType } from 'src/app/data/document-type'
@@ -26,6 +26,7 @@ import { MailAccountService } from 'src/app/services/rest/mail-account.service'
 import { MailRuleService } from 'src/app/services/rest/mail-rule.service'
 import { UserService } from 'src/app/services/rest/user.service'
 import { SettingsService } from 'src/app/services/settings.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { CheckComponent } from '../../input/check/check.component'
 import { NumberComponent } from '../../input/number/number.component'
 import { SelectComponent } from '../../input/select/select.component'
@@ -158,17 +159,45 @@ export class MailRuleEditDialogComponent extends EditDialogComponent<MailRule> {
   private readonly accountService = inject(MailAccountService)
   private readonly correspondentService = inject(CorrespondentService)
   private readonly documentTypeService = inject(DocumentTypeService)
+  private readonly toastService = inject(ToastService)
 
   readonly accounts = toSignal(
-    this.accountService.listAll().pipe(map((result) => result.results)),
+    this.accountService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError(
+          $localize`Error retrieving mail accounts`,
+          error
+        )
+        return of([])
+      })
+    ),
     { initialValue: undefined as MailAccount[] }
   )
   readonly correspondents = toSignal(
-    this.correspondentService.listAll().pipe(map((result) => result.results)),
+    this.correspondentService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError(
+          $localize`Error retrieving correspondents`,
+          error
+        )
+        return of([])
+      })
+    ),
     { initialValue: undefined as Correspondent[] }
   )
   readonly documentTypes = toSignal(
-    this.documentTypeService.listAll().pipe(map((result) => result.results)),
+    this.documentTypeService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError(
+          $localize`Error retrieving document types`,
+          error
+        )
+        return of([])
+      })
+    ),
     { initialValue: undefined as DocumentType[] }
   )
 
diff --git a/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.spec.ts b/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.spec.ts
index f50bf830e..f63a30657 100644
--- a/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.spec.ts
+++ b/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.spec.ts
@@ -81,6 +81,23 @@ describe('UserEditDialogComponent', () => {
     fixture.detectChanges()
   })
 
+  it('should use an empty group list when retrieval fails', () => {
+    const toastSpy = jest.spyOn(toastService, 'showError')
+    jest
+      .spyOn(TestBed.inject(GroupService), 'listAll')
+      .mockReturnValue(throwError(() => new Error('Forbidden')))
+
+    const failedFixture = TestBed.createComponent(UserEditDialogComponent)
+    const failedComponent = failedFixture.componentInstance
+
+    expect(failedComponent.groups()).toEqual([])
+    expect(() => failedFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving groups',
+      expect.any(Error)
+    )
+  })
+
   it('should support create and edit modes', () => {
     component.dialogMode.set(EditDialogMode.CREATE)
     const createTitleSpy = jest.spyOn(component, 'getCreateTitle')
diff --git a/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.ts b/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.ts
index 426fc67e2..cd9577545 100644
--- a/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.ts
+++ b/src-ui/src/app/components/common/edit-dialog/user-edit-dialog/user-edit-dialog.component.ts
@@ -6,7 +6,7 @@ import {
   FormsModule,
   ReactiveFormsModule,
 } from '@angular/forms'
-import { first, map } from 'rxjs'
+import { catchError, first, map, of } from 'rxjs'
 import { EditDialogComponent } from 'src/app/components/common/edit-dialog/edit-dialog.component'
 import { Group } from 'src/app/data/group'
 import { User } from 'src/app/data/user'
@@ -42,7 +42,13 @@ export class UserEditDialogComponent
   private readonly groupsService = inject(GroupService)
 
   readonly groups = toSignal(
-    this.groupsService.listAll().pipe(map((result) => result.results)),
+    this.groupsService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError($localize`Error retrieving groups`, error)
+        return of([])
+      })
+    ),
     { initialValue: undefined as Group[] }
   )
   readonly passwordIsSet = signal(false)
diff --git a/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.spec.ts b/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.spec.ts
index 3c4d8f790..a3c4bd64c 100644
--- a/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.spec.ts
+++ b/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.spec.ts
@@ -11,7 +11,7 @@ import {
 } from '@angular/forms'
 import { NgbActiveModal, NgbModule } from '@ng-bootstrap/ng-bootstrap'
 import { NgSelectModule } from '@ng-select/ng-select'
-import { of } from 'rxjs'
+import { of, throwError } from 'rxjs'
 import { CustomFieldQueriesModel } from 'src/app/components/common/custom-fields-query-dropdown/custom-fields-query-dropdown.component'
 import { CustomFieldDataType } from 'src/app/data/custom-field'
 import { CustomFieldQueryLogicalOperator } from 'src/app/data/custom-field-query'
@@ -39,6 +39,7 @@ import { DocumentTypeService } from 'src/app/services/rest/document-type.service
 import { MailRuleService } from 'src/app/services/rest/mail-rule.service'
 import { StoragePathService } from 'src/app/services/rest/storage-path.service'
 import { SettingsService } from 'src/app/services/settings.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { CustomFieldQueryExpression } from 'src/app/utils/custom-field-query-element'
 import { ConfirmButtonComponent } from '../../confirm-button/confirm-button.component'
 import { NumberComponent } from '../../input/number/number.component'
@@ -206,6 +207,44 @@ describe('WorkflowEditDialogComponent', () => {
     settingsService.set(SETTINGS_KEYS.AI_ENABLED, ai)
   }
 
+  it('should use empty related object lists when access is forbidden', () => {
+    const forbidden = () => throwError(() => new Error('Forbidden'))
+    const toastSpy = jest.spyOn(TestBed.inject(ToastService), 'showError')
+    jest
+      .spyOn(TestBed.inject(CorrespondentService), 'listAll')
+      .mockReturnValue(forbidden())
+    jest
+      .spyOn(TestBed.inject(DocumentTypeService), 'listAll')
+      .mockReturnValue(forbidden())
+    jest
+      .spyOn(TestBed.inject(StoragePathService), 'listAll')
+      .mockReturnValue(forbidden())
+    jest
+      .spyOn(TestBed.inject(MailRuleService), 'listAll')
+      .mockReturnValue(forbidden())
+    jest
+      .spyOn(TestBed.inject(CustomFieldsService), 'listAll')
+      .mockReturnValue(forbidden())
+
+    const forbiddenFixture = TestBed.createComponent(
+      WorkflowEditDialogComponent
+    )
+    const forbiddenComponent = forbiddenFixture.componentInstance
+
+    expect(forbiddenComponent.correspondents()).toEqual([])
+    expect(forbiddenComponent.documentTypes()).toEqual([])
+    expect(forbiddenComponent.storagePaths()).toEqual([])
+    expect(forbiddenComponent.mailRules()).toEqual([])
+    expect(forbiddenComponent.customFields()).toEqual([])
+    expect(forbiddenComponent.dateCustomFields()).toEqual([])
+    expect(() => forbiddenFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledTimes(1)
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Some workflow options could not be loaded.',
+      expect.any(Error)
+    )
+  })
+
   it('should support create and edit modes, support adding triggers and actions on new workflow', () => {
     component.dialogMode.set(EditDialogMode.CREATE)
     const createTitleSpy = jest.spyOn(component, 'getCreateTitle')
diff --git a/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.ts b/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.ts
index 76f9ac2af..a89c87cf9 100644
--- a/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.ts
+++ b/src-ui/src/app/components/common/edit-dialog/workflow-edit-dialog/workflow-edit-dialog.component.ts
@@ -16,7 +16,7 @@ import {
 } from '@angular/forms'
 import { NgbAccordionModule } from '@ng-bootstrap/ng-bootstrap'
 import { NgxBootstrapIconsModule } from 'ngx-bootstrap-icons'
-import { Subscription, map, takeUntil } from 'rxjs'
+import { Subscription, catchError, map, of, takeUntil } from 'rxjs'
 import { Correspondent } from 'src/app/data/correspondent'
 import { CustomField, CustomFieldDataType } from 'src/app/data/custom-field'
 import { DocumentType } from 'src/app/data/document-type'
@@ -48,6 +48,7 @@ import { StoragePathService } from 'src/app/services/rest/storage-path.service'
 import { UserService } from 'src/app/services/rest/user.service'
 import { WorkflowService } from 'src/app/services/rest/workflow.service'
 import { SettingsService } from 'src/app/services/settings.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { CustomFieldQueryExpression } from 'src/app/utils/custom-field-query-element'
 import { ConfirmButtonComponent } from '../../confirm-button/confirm-button.component'
 import {
@@ -512,26 +513,43 @@ export class WorkflowEditDialogComponent
   private readonly storagePathService = inject(StoragePathService)
   private readonly mailRuleService = inject(MailRuleService)
   private readonly customFieldsService = inject(CustomFieldsService)
+  private readonly toastService = inject(ToastService)
+  private relatedObjectLoadErrorShown = false
 
   readonly templates = signal<Workflow[]>(undefined)
   readonly correspondents = toSignal(
-    this.correspondentService.listAll().pipe(map((result) => result.results)),
+    this.correspondentService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => this.handleRelatedObjectLoadError(error))
+    ),
     { initialValue: undefined as Correspondent[] }
   )
   readonly documentTypes = toSignal(
-    this.documentTypeService.listAll().pipe(map((result) => result.results)),
+    this.documentTypeService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => this.handleRelatedObjectLoadError(error))
+    ),
     { initialValue: undefined as DocumentType[] }
   )
   readonly storagePaths = toSignal(
-    this.storagePathService.listAll().pipe(map((result) => result.results)),
+    this.storagePathService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => this.handleRelatedObjectLoadError(error))
+    ),
     { initialValue: undefined as StoragePath[] }
   )
   readonly mailRules = toSignal(
-    this.mailRuleService.listAll().pipe(map((result) => result.results)),
+    this.mailRuleService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => this.handleRelatedObjectLoadError(error))
+    ),
     { initialValue: undefined as MailRule[] }
   )
   readonly customFields = toSignal(
-    this.customFieldsService.listAll().pipe(map((result) => result.results)),
+    this.customFieldsService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => this.handleRelatedObjectLoadError(error))
+    ),
     { initialValue: undefined as CustomField[] }
   )
   readonly dateCustomFields = computed(() =>
@@ -545,6 +563,17 @@ export class WorkflowEditDialogComponent
     SETTINGS_KEYS.AI_ENABLED
   )
 
+  private handleRelatedObjectLoadError(error) {
+    if (!this.relatedObjectLoadErrorShown) {
+      this.relatedObjectLoadErrorShown = true
+      this.toastService.showError(
+        $localize`Some workflow options could not be loaded.`,
+        error
+      )
+    }
+    return of([])
+  }
+
   expandedItem: number = null
 
   private readonly triggerFilterOptionsMap = new WeakMap<
diff --git a/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.spec.ts b/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.spec.ts
index 0bfed7b37..6a43d5cd3 100644
--- a/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.spec.ts
+++ b/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.spec.ts
@@ -7,8 +7,9 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms'
 import { NgSelectModule } from '@ng-select/ng-select'
-import { of } from 'rxjs'
+import { of, throwError } from 'rxjs'
 import { GroupService } from 'src/app/services/rest/group.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { PermissionsGroupComponent } from './permissions-group.component'
 
 describe('PermissionsGroupComponent', () => {
@@ -60,4 +61,19 @@ describe('PermissionsGroupComponent', () => {
     expect(component.value).toEqual({ id: 2, name: 'Group 2' })
     expect(groupServiceSpy).toHaveBeenCalled()
   })
+
+  it('should use an empty group list when retrieval fails', () => {
+    const toastSpy = jest.spyOn(TestBed.inject(ToastService), 'showError')
+    groupServiceSpy.mockReturnValue(throwError(() => new Error('Forbidden')))
+
+    const failedFixture = TestBed.createComponent(PermissionsGroupComponent)
+    const failedComponent = failedFixture.componentInstance
+
+    expect(failedComponent.groups()).toEqual([])
+    expect(() => failedFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving groups',
+      expect.any(Error)
+    )
+  })
 })
diff --git a/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.ts b/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.ts
index 7367a9ac0..60fd8ace3 100644
--- a/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.ts
+++ b/src-ui/src/app/components/common/input/permissions/permissions-group/permissions-group.component.ts
@@ -6,9 +6,10 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms'
 import { NgSelectComponent } from '@ng-select/ng-select'
-import { map } from 'rxjs/operators'
+import { catchError, map, of } from 'rxjs'
 import { Group } from 'src/app/data/group'
 import { GroupService } from 'src/app/services/rest/group.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { AbstractInputComponent } from '../../abstract-input'
 
 @Component({
@@ -26,8 +27,15 @@ import { AbstractInputComponent } from '../../abstract-input'
 })
 export class PermissionsGroupComponent extends AbstractInputComponent<Group> {
   private readonly groupService = inject(GroupService)
+  private readonly toastService = inject(ToastService)
   readonly groups = toSignal(
-    this.groupService.listAll().pipe(map((result) => result.results)),
+    this.groupService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError($localize`Error retrieving groups`, error)
+        return of([])
+      })
+    ),
     { initialValue: undefined as Group[] }
   )
 }
diff --git a/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.spec.ts b/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.spec.ts
index 0d7a525ae..b1b4e83d2 100644
--- a/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.spec.ts
+++ b/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.spec.ts
@@ -7,8 +7,9 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms'
 import { NgSelectModule } from '@ng-select/ng-select'
-import { of } from 'rxjs'
+import { of, throwError } from 'rxjs'
 import { UserService } from 'src/app/services/rest/user.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { PermissionsUserComponent } from './permissions-user.component'
 
 describe('PermissionsUserComponent', () => {
@@ -60,4 +61,19 @@ describe('PermissionsUserComponent', () => {
     expect(component.value).toEqual({ id: 2, name: 'User 2' })
     expect(userServiceSpy).toHaveBeenCalled()
   })
+
+  it('should use an empty user list when retrieval fails', () => {
+    const toastSpy = jest.spyOn(TestBed.inject(ToastService), 'showError')
+    userServiceSpy.mockReturnValue(throwError(() => new Error('Forbidden')))
+
+    const failedFixture = TestBed.createComponent(PermissionsUserComponent)
+    const failedComponent = failedFixture.componentInstance
+
+    expect(failedComponent.users()).toEqual([])
+    expect(() => failedFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving users',
+      expect.any(Error)
+    )
+  })
 })
diff --git a/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.ts b/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.ts
index f63ebecc4..cf0ee884b 100644
--- a/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.ts
+++ b/src-ui/src/app/components/common/input/permissions/permissions-user/permissions-user.component.ts
@@ -6,9 +6,10 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms'
 import { NgSelectComponent } from '@ng-select/ng-select'
-import { map } from 'rxjs/operators'
+import { catchError, map, of } from 'rxjs'
 import { User } from 'src/app/data/user'
 import { UserService } from 'src/app/services/rest/user.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { AbstractInputComponent } from '../../abstract-input'
 
 @Component({
@@ -26,8 +27,15 @@ import { AbstractInputComponent } from '../../abstract-input'
 })
 export class PermissionsUserComponent extends AbstractInputComponent<User[]> {
   private readonly userService = inject(UserService)
+  private readonly toastService = inject(ToastService)
   readonly users = toSignal(
-    this.userService.listAll().pipe(map((result) => result.results)),
+    this.userService.listAll().pipe(
+      map((result) => result.results),
+      catchError((error) => {
+        this.toastService.showError($localize`Error retrieving users`, error)
+        return of([])
+      })
+    ),
     { initialValue: undefined as User[] }
   )
 }
diff --git a/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.spec.ts b/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.spec.ts
index 004b2df0b..44da05b88 100644
--- a/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.spec.ts
+++ b/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.spec.ts
@@ -4,8 +4,9 @@ import { ComponentFixture, TestBed } from '@angular/core/testing'
 import { FormsModule, ReactiveFormsModule } from '@angular/forms'
 import { NgbActiveModal, NgbModule } from '@ng-bootstrap/ng-bootstrap'
 import { NgSelectModule } from '@ng-select/ng-select'
-import { of } from 'rxjs'
+import { of, throwError } from 'rxjs'
 import { UserService } from 'src/app/services/rest/user.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { PermissionsFormComponent } from '../input/permissions/permissions-form/permissions-form.component'
 import { PermissionsGroupComponent } from '../input/permissions/permissions-group/permissions-group.component'
 import { PermissionsUserComponent } from '../input/permissions/permissions-user/permissions-user.component'
@@ -77,6 +78,23 @@ describe('PermissionsDialogComponent', () => {
     fixture.detectChanges()
   })
 
+  it('should use an empty user list when retrieval fails', () => {
+    const toastSpy = jest.spyOn(TestBed.inject(ToastService), 'showError')
+    jest
+      .spyOn(TestBed.inject(UserService), 'listAll')
+      .mockReturnValue(throwError(() => new Error('Forbidden')))
+
+    const failedFixture = TestBed.createComponent(PermissionsDialogComponent)
+    const failedComponent = failedFixture.componentInstance
+
+    expect(failedComponent.users()).toEqual([])
+    expect(() => failedFixture.detectChanges()).not.toThrow()
+    expect(toastSpy).toHaveBeenCalledWith(
+      'Error retrieving users',
+      expect.any(Error)
+    )
+  })
+
   it('should return permissions', () => {
     expect(component.permissions).toEqual({
       owner: null,
diff --git a/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.ts b/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.ts
index 1194886fd..89138bb92 100644
--- a/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.ts
+++ b/src-ui/src/app/components/common/permissions-dialog/permissions-dialog.component.ts
@@ -14,10 +14,11 @@ import {
   ReactiveFormsModule,
 } from '@angular/forms'
 import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
-import { map } from 'rxjs'
+import { catchError, map, of } from 'rxjs'
 import { ObjectWithPermissions } from 'src/app/data/object-with-permissions'
 import { User } from 'src/app/data/user'
 import { UserService } from 'src/app/services/rest/user.service'
+import { ToastService } from 'src/app/services/toast.service'
 import { PermissionsFormComponent } from '../input/permissions/permissions-form/permissions-form.component'
 import { SwitchComponent } from '../input/switch/switch.component'
 
@@ -35,9 +36,16 @@ import { SwitchComponent } from '../input/switch/switch.component'
 export class PermissionsDialogComponent {
   activeModal = inject(NgbActiveModal)
   private userService = inject(UserService)
+  private toastService = inject(ToastService)
 
   readonly users = toSignal(
-    this.userService.listAll().pipe(map((r) => r.results)),
+    this.userService.listAll().pipe(
+      map((r) => r.results),
+      catchError((error) => {
+        this.toastService.showError($localize`Error retrieving users`, error)
+        return of([])
+      })
+    ),
     { initialValue: undefined as User[] }
   )
   readonly title = signal($localize`Set permissions`)