diff --git a/client/src/app/gateways/repositories/polls/vote-repository.service/vote-repository.service.ts b/client/src/app/gateways/repositories/polls/vote-repository.service/vote-repository.service.ts
index 34be35d030..e78cc4f13b 100644
--- a/client/src/app/gateways/repositories/polls/vote-repository.service/vote-repository.service.ts
+++ b/client/src/app/gateways/repositories/polls/vote-repository.service/vote-repository.service.ts
@@ -132,11 +132,13 @@ export class VoteRepositoryService extends BaseMeetingRelatedRepository<ViewVote
         }
 
         const results: HasVotedResponse = await this.http.get(`${HAS_VOTED_URL}?ids=${ids.join()}`);
-        for (const pollId of Object.keys(results)) {
-            const subscription = this._subscribedPolls.get(+pollId);
-            const currentVal = subscription.current.value;
-            if (JSON.stringify(currentVal) !== JSON.stringify(results[pollId])) {
-                subscription.current.next(results[pollId]);
+        if (results) {
+            for (const pollId of Object.keys(results)) {
+                const subscription = this._subscribedPolls.get(+pollId);
+                const currentVal = subscription.current.value;
+                if (JSON.stringify(currentVal) !== JSON.stringify(results[pollId])) {
+                    subscription.current.next(results[pollId]);
+                }
             }
         }
     }
diff --git a/client/src/app/site/modules/global-headbar/components/account-button/account-button.component.ts b/client/src/app/site/modules/global-headbar/components/account-button/account-button.component.ts
index 18c2b5578a..784b443933 100644
--- a/client/src/app/site/modules/global-headbar/components/account-button/account-button.component.ts
+++ b/client/src/app/site/modules/global-headbar/components/account-button/account-button.component.ts
@@ -224,6 +224,6 @@ export class AccountButtonComponent extends BaseUiComponent implements OnInit {
         } else {
             stringForUserPresent = this.translate.instant(`Your account is not in this meeting.`);
         }
-        return this.user.short_name + ': ' + stringForUserPresent;
+        return this.user?.short_name + ': ' + stringForUserPresent;
     }
 }
diff --git a/client/src/app/site/pages/meetings/pages/participants/pages/participant-detail/components/participant-detail-view/participant-detail-view.component.ts b/client/src/app/site/pages/meetings/pages/participants/pages/participant-detail/components/participant-detail-view/participant-detail-view.component.ts
index 39b248047d..efa331ed9a 100644
--- a/client/src/app/site/pages/meetings/pages/participants/pages/participant-detail/components/participant-detail-view/participant-detail-view.component.ts
+++ b/client/src/app/site/pages/meetings/pages/participants/pages/participant-detail/components/participant-detail-view/participant-detail-view.component.ts
@@ -133,7 +133,7 @@ export class ParticipantDetailViewComponent extends BaseMeetingComponent {
     public readonly groups: Observable<ViewGroup[]>;
 
     public get isMeetingAdminAndEditSelf(): boolean {
-        return this.operator.isMeetingAdmin && this.user.id === this.operator.user?.id;
+        return this.operator.isMeetingAdmin && this.user?.id === this.operator.user?.id;
     }
 
     public get showVoteWeight(): boolean {
diff --git a/client/src/app/site/services/operator.service.ts b/client/src/app/site/services/operator.service.ts
index 755a84d527..05c5cd5f3d 100644
--- a/client/src/app/site/services/operator.service.ts
+++ b/client/src/app/site/services/operator.service.ts
@@ -122,7 +122,7 @@ export class OperatorService {
     }
 
     public get onlyMeeting(): Id {
-        return this.user.onlyMeeting;
+        return this.user?.onlyMeeting;
     }
 
     public get canChangeOwnPassword(): boolean {
@@ -411,7 +411,7 @@ export class OperatorService {
 
     public isInMeeting(meetingId: Id): boolean {
         const meeting = this.meetingRepo.getViewModel(meetingId);
-        return (meeting?.enable_anonymous && this.isAnonymous) || this.user.ensuredMeetingIds.includes(meetingId);
+        return (meeting?.enable_anonymous && this.isAnonymous) || this.user?.ensuredMeetingIds.includes(meetingId);
     }
 
     public hasCommitteeManagementRights(committee_id: number): boolean {
@@ -643,7 +643,7 @@ export class OperatorService {
         ) {
             return true;
         }
-        const groups = this.user.groups(meetingId);
+        const groups = this.user?.groups(meetingId);
         if (!groups || !groups.length) {
             return false;
         } else if (
@@ -657,7 +657,7 @@ export class OperatorService {
 
     public isAllowedWithDelegation(...appliedSettings: DelegationSetting[]): boolean {
         return (
-            !this.user.getMeetingUser(this.activeMeetingId)?.vote_delegated_to_id ||
+            !this.user?.getMeetingUser(this.activeMeetingId)?.vote_delegated_to_id ||
             !appliedSettings.some(appliedSetting => this.meetingSettings.instant(appliedSetting as keyof Settings))
         );
     }
diff --git a/client/src/app/ui/modules/sidenav/modules/easter-egg/modules/chess-dialog/services/chess-challenge.service.ts b/client/src/app/ui/modules/sidenav/modules/easter-egg/modules/chess-dialog/services/chess-challenge.service.ts
index 4813f85bfc..4a4400926e 100644
--- a/client/src/app/ui/modules/sidenav/modules/easter-egg/modules/chess-dialog/services/chess-challenge.service.ts
+++ b/client/src/app/ui/modules/sidenav/modules/easter-egg/modules/chess-dialog/services/chess-challenge.service.ts
@@ -3,7 +3,6 @@ import { MatDialog } from '@angular/material/dialog';
 import { TranslateService } from '@ngx-translate/core';
 import { NotifyResponse, NotifyService } from 'src/app/gateways/notify.service';
 import { mediumDialogSettings } from 'src/app/infrastructure/utils/dialog-settings';
-import { OperatorService } from 'src/app/site/services/operator.service';
 import { PromptService } from 'src/app/ui/modules/prompt-dialog';
 
 import { ChessDialogModule } from '../chess-dialog.module';
@@ -14,7 +13,6 @@ import { ChessDialogModule } from '../chess-dialog.module';
 export class ChessChallengeService {
     public constructor(
         private notifyService: NotifyService,
-        private op: OperatorService,
         private dialog: MatDialog,
         private translate: TranslateService,
         private prompt: PromptService