diff --git a/client/src/app/core/services/collectionStringModelMapper.service.ts b/client/src/app/core/services/collectionStringModelMapper.service.ts
index 0cea0511f..9c749f085 100644
--- a/client/src/app/core/services/collectionStringModelMapper.service.ts
+++ b/client/src/app/core/services/collectionStringModelMapper.service.ts
@@ -12,20 +12,7 @@ export class CollectionStringModelMapperService {
      * Mapps collection strings to model constructors. Accessed by {@method registerCollectionElement} and
      * {@method getCollectionStringType}.
      */
-    private static collectionStringsTypeMapping: { [collectionString: string]: ModelConstructor<BaseModel> } = {};
-
-    /**
-     * Returns the collection string of a given ModelConstructor or undefined, if it is not registered.
-     * @param ctor
-     * @deprecated Should inject this service and don't use the static functions.
-     */
-    public static getCollectionString(ctor: ModelConstructor<BaseModel>): string {
-        return Object.keys(CollectionStringModelMapperService.collectionStringsTypeMapping).find(
-            (collectionString: string) => {
-                return ctor === CollectionStringModelMapperService.collectionStringsTypeMapping[collectionString];
-            }
-        );
-    }
+    private collectionStringsTypeMapping: { [collectionString: string]: ModelConstructor<BaseModel> } = {};
 
     /**
      * Constructor to create the NotifyService. Registers itself to the WebsocketService.
@@ -39,7 +26,7 @@ export class CollectionStringModelMapperService {
      * @param type
      */
     public registerCollectionElement(collectionString: string, type: ModelConstructor<BaseModel>): void {
-        CollectionStringModelMapperService.collectionStringsTypeMapping[collectionString] = type;
+        this.collectionStringsTypeMapping[collectionString] = type;
     }
 
     /**
@@ -47,7 +34,7 @@ export class CollectionStringModelMapperService {
      * @param collectionString the requested collection
      */
     public getModelConstructor(collectionString: string): ModelConstructor<BaseModel> {
-        return CollectionStringModelMapperService.collectionStringsTypeMapping[collectionString];
+        return this.collectionStringsTypeMapping[collectionString];
     }
 
     /**
@@ -55,10 +42,8 @@ export class CollectionStringModelMapperService {
      * @param ctor
      */
     public getCollectionString(ctor: ModelConstructor<BaseModel>): string {
-        return Object.keys(CollectionStringModelMapperService.collectionStringsTypeMapping).find(
-            (collectionString: string) => {
-                return ctor === CollectionStringModelMapperService.collectionStringsTypeMapping[collectionString];
-            }
-        );
+        return Object.keys(this.collectionStringsTypeMapping).find((collectionString: string) => {
+            return ctor === this.collectionStringsTypeMapping[collectionString];
+        });
     }
 }
diff --git a/client/src/app/site/agenda/services/agenda-repository.service.spec.ts b/client/src/app/site/agenda/services/agenda-repository.service.spec.ts
index 870d49958..ab4c893ae 100644
--- a/client/src/app/site/agenda/services/agenda-repository.service.spec.ts
+++ b/client/src/app/site/agenda/services/agenda-repository.service.spec.ts
@@ -1,10 +1,12 @@
 import { TestBed, inject } from '@angular/core/testing';
 
 import { AgendaRepositoryService } from './agenda-repository.service';
+import { E2EImportsModule } from 'e2e-imports.module';
 
 describe('AgendaRepositoryService', () => {
     beforeEach(() => {
         TestBed.configureTestingModule({
+            imports: [E2EImportsModule],
             providers: [AgendaRepositoryService]
         });
     });
diff --git a/client/src/app/site/agenda/services/agenda-repository.service.ts b/client/src/app/site/agenda/services/agenda-repository.service.ts
index 7cb6029dc..a747179ff 100644
--- a/client/src/app/site/agenda/services/agenda-repository.service.ts
+++ b/client/src/app/site/agenda/services/agenda-repository.service.ts
@@ -7,6 +7,7 @@ import { ViewItem } from '../models/view-item';
 import { AgendaBaseModel } from '../../../shared/models/base/agenda-base-model';
 import { BaseModel } from '../../../shared/models/base/base-model';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository service for users
@@ -17,8 +18,8 @@ import { Identifiable } from '../../../shared/models/base/identifiable';
     providedIn: 'root'
 })
 export class AgendaRepositoryService extends BaseRepository<ViewItem, Item> {
-    public constructor(DS: DataStoreService) {
-        super(DS, Item);
+    public constructor(DS: DataStoreService, mapperService: CollectionStringModelMapperService) {
+        super(DS, mapperService, Item);
     }
 
     /**
diff --git a/client/src/app/site/assignments/services/assignment-repository.service.ts b/client/src/app/site/assignments/services/assignment-repository.service.ts
index 54b1c3c3d..4d00e5431 100644
--- a/client/src/app/site/assignments/services/assignment-repository.service.ts
+++ b/client/src/app/site/assignments/services/assignment-repository.service.ts
@@ -7,6 +7,7 @@ import { Item } from '../../../shared/models/agenda/item';
 import { BaseRepository } from '../../base/base-repository';
 import { DataStoreService } from '../../../core/services/data-store.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Service for Assignments.
@@ -21,8 +22,8 @@ export class AssignmentRepositoryService extends BaseRepository<ViewAssignment,
      * Constructor for the Assignment Repository.
      *
      */
-    public constructor(DS: DataStoreService) {
-        super(DS, Assignment, [User, Item, Tag]);
+    public constructor(DS: DataStoreService, mapperService: CollectionStringModelMapperService) {
+        super(DS, mapperService, Assignment, [User, Item, Tag]);
     }
 
     public async update(assignment: Partial<Assignment>, viewAssignment: ViewAssignment): Promise<void> {
diff --git a/client/src/app/site/base/base-repository.ts b/client/src/app/site/base/base-repository.ts
index c98d9ba57..7327891f4 100644
--- a/client/src/app/site/base/base-repository.ts
+++ b/client/src/app/site/base/base-repository.ts
@@ -30,6 +30,7 @@ export abstract class BaseRepository<V extends BaseViewModel, M extends BaseMode
      */
     public constructor(
         protected DS: DataStoreService,
+        protected collectionStringModelMapperService: CollectionStringModelMapperService,
         protected baseModelCtor: ModelConstructor<M>,
         protected depsModelCtors?: ModelConstructor<BaseModel>[]
     ) {
@@ -67,7 +68,7 @@ export abstract class BaseRepository<V extends BaseViewModel, M extends BaseMode
 
         // Watch the Observables for deleting
         this.DS.deletedObservable.subscribe(model => {
-            if (model.collection === CollectionStringModelMapperService.getCollectionString(this.baseModelCtor)) {
+            if (model.collection === this.collectionStringModelMapperService.getCollectionString(this.baseModelCtor)) {
                 delete this.viewModelStore[model.id];
                 this.updateAllObservables(model.id);
             }
diff --git a/client/src/app/site/config/services/config-repository.service.ts b/client/src/app/site/config/services/config-repository.service.ts
index afdde0a24..25fbcb10e 100644
--- a/client/src/app/site/config/services/config-repository.service.ts
+++ b/client/src/app/site/config/services/config-repository.service.ts
@@ -8,6 +8,7 @@ import { DataStoreService } from '../../../core/services/data-store.service';
 import { ConstantsService } from '../../../core/services/constants.service';
 import { HttpService } from '../../../core/services/http.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Holds a single config item.
@@ -86,8 +87,13 @@ export class ConfigRepositoryService extends BaseRepository<ViewConfig, Config>
     /**
      * Constructor for ConfigRepositoryService. Requests the constants from the server and creates the config group structure.
      */
-    public constructor(DS: DataStoreService, private constantsService: ConstantsService, private http: HttpService) {
-        super(DS, Config);
+    public constructor(
+        DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private constantsService: ConstantsService,
+        private http: HttpService
+    ) {
+        super(DS, mapperService, Config);
 
         this.constantsService.get('OpenSlidesConfigVariables').subscribe(constant => {
             this.createConfigStructure(constant);
@@ -186,10 +192,7 @@ export class ConfigRepositoryService extends BaseRepository<ViewConfig, Config>
         updatedConfig.patchValues(viewConfig.config);
         updatedConfig.patchValues(config);
         // TODO: Use datasendService, if it can switch correctly between put, post and patch
-        await this.http.put(
-            'rest/' + updatedConfig.collectionString + '/' + updatedConfig.key + '/',
-            updatedConfig
-        );
+        await this.http.put('rest/' + updatedConfig.collectionString + '/' + updatedConfig.key + '/', updatedConfig);
     }
 
     /**
diff --git a/client/src/app/site/mediafiles/services/mediafile-repository.service.ts b/client/src/app/site/mediafiles/services/mediafile-repository.service.ts
index 0b48b564e..b5c71ac70 100644
--- a/client/src/app/site/mediafiles/services/mediafile-repository.service.ts
+++ b/client/src/app/site/mediafiles/services/mediafile-repository.service.ts
@@ -6,6 +6,7 @@ import { Mediafile } from '../../../shared/models/mediafiles/mediafile';
 import { User } from '../../../shared/models/users/user';
 import { DataStoreService } from '../../../core/services/data-store.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository for files
@@ -18,8 +19,8 @@ export class MediafileRepositoryService extends BaseRepository<ViewMediafile, Me
      * Consturctor for the file repo
      * @param DS the DataStore
      */
-    public constructor(DS: DataStoreService) {
-        super(DS, Mediafile, [User]);
+    public constructor(DS: DataStoreService, mapperService: CollectionStringModelMapperService) {
+        super(DS, mapperService, Mediafile, [User]);
     }
 
     /**
diff --git a/client/src/app/site/motions/services/category-repository.service.ts b/client/src/app/site/motions/services/category-repository.service.ts
index 48cbdf4a4..9aca4ba5b 100644
--- a/client/src/app/site/motions/services/category-repository.service.ts
+++ b/client/src/app/site/motions/services/category-repository.service.ts
@@ -8,6 +8,7 @@ import { Motion } from '../../../shared/models/motions/motion';
 import { CategoryNumbering } from '../models/category-numbering';
 import { HttpService } from '../../../core/services/http.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for Categories
@@ -31,10 +32,11 @@ export class CategoryRepositoryService extends BaseRepository<ViewCategory, Cate
      */
     public constructor(
         protected DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
         private dataSend: DataSendService,
         private httpService: HttpService
     ) {
-        super(DS, Category);
+        super(DS, mapperService, Category);
     }
 
     protected createViewModel(category: Category): ViewCategory {
diff --git a/client/src/app/site/motions/services/change-recommendation-repository.service.ts b/client/src/app/site/motions/services/change-recommendation-repository.service.ts
index b34c26bb8..5574d9ef0 100644
--- a/client/src/app/site/motions/services/change-recommendation-repository.service.ts
+++ b/client/src/app/site/motions/services/change-recommendation-repository.service.ts
@@ -11,6 +11,7 @@ import { DataStoreService } from '../../../core/services/data-store.service';
 import { MotionChangeReco } from '../../../shared/models/motions/motion-change-reco';
 import { ViewChangeReco } from '../models/view-change-reco';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for change recommendations
@@ -34,8 +35,12 @@ export class ChangeRecommendationRepositoryService extends BaseRepository<ViewCh
      * @param DS
      * @param dataSend
      */
-    public constructor(DS: DataStoreService, private dataSend: DataSendService) {
-        super(DS, MotionChangeReco, [Category, User, Workflow]);
+    public constructor(
+        DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService
+    ) {
+        super(DS, mapperService, MotionChangeReco, [Category, User, Workflow]);
     }
 
     /**
diff --git a/client/src/app/site/motions/services/motion-comment-section-repository.service.ts b/client/src/app/site/motions/services/motion-comment-section-repository.service.ts
index 19edc8223..0ff9e8d15 100644
--- a/client/src/app/site/motions/services/motion-comment-section-repository.service.ts
+++ b/client/src/app/site/motions/services/motion-comment-section-repository.service.ts
@@ -6,6 +6,7 @@ import { ViewMotionCommentSection } from '../models/view-motion-comment-section'
 import { MotionCommentSection } from '../../../shared/models/motions/motion-comment-section';
 import { Group } from '../../../shared/models/users/group';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for Categories
@@ -30,8 +31,12 @@ export class MotionCommentSectionRepositoryService extends BaseRepository<
      * Handles CRUD using an observer to the DataStore
      * @param DataSend
      */
-    public constructor(protected DS: DataStoreService, private dataSend: DataSendService) {
-        super(DS, MotionCommentSection, [Group]);
+    public constructor(
+        protected DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService
+    ) {
+        super(DS, mapperService, MotionCommentSection, [Group]);
     }
 
     protected createViewModel(section: MotionCommentSection): ViewMotionCommentSection {
diff --git a/client/src/app/site/motions/services/motion-repository.service.ts b/client/src/app/site/motions/services/motion-repository.service.ts
index d5ffa43cc..45dba692d 100644
--- a/client/src/app/site/motions/services/motion-repository.service.ts
+++ b/client/src/app/site/motions/services/motion-repository.service.ts
@@ -15,6 +15,7 @@ import { ViewChangeReco } from '../models/view-change-reco';
 import { MotionChangeReco } from '../../../shared/models/motions/motion-change-reco';
 import { ViewUnifiedChange } from '../models/view-unified-change';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for motions (and potentially categories)
@@ -42,11 +43,12 @@ export class MotionRepositoryService extends BaseRepository<ViewMotion, Motion>
      */
     public constructor(
         DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
         private dataSend: DataSendService,
         private readonly lineNumbering: LinenumberingService,
         private readonly diff: DiffService
     ) {
-        super(DS, Motion, [Category, User, Workflow]);
+        super(DS, mapperService, Motion, [Category, User, Workflow]);
     }
 
     /**
diff --git a/client/src/app/site/motions/services/statute-paragraph-repository.service.ts b/client/src/app/site/motions/services/statute-paragraph-repository.service.ts
index 8d959dfea..c3625c79f 100644
--- a/client/src/app/site/motions/services/statute-paragraph-repository.service.ts
+++ b/client/src/app/site/motions/services/statute-paragraph-repository.service.ts
@@ -5,6 +5,7 @@ import { BaseRepository } from '../../base/base-repository';
 import { ViewStatuteParagraph } from '../models/view-statute-paragraph';
 import { StatuteParagraph } from '../../../shared/models/motions/statute-paragraph';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for statute paragraphs
@@ -23,8 +24,12 @@ export class StatuteParagraphRepositoryService extends BaseRepository<ViewStatut
      * Handles CRUD using an observer to the DataStore
      * @param DataSend
      */
-    public constructor(protected DS: DataStoreService, private dataSend: DataSendService) {
-        super(DS, StatuteParagraph);
+    public constructor(
+        DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService
+    ) {
+        super(DS, mapperService, StatuteParagraph);
     }
 
     protected createViewModel(statuteParagraph: StatuteParagraph): ViewStatuteParagraph {
diff --git a/client/src/app/site/tags/services/tag-repository.service.ts b/client/src/app/site/tags/services/tag-repository.service.ts
index fba6ca744..902574335 100644
--- a/client/src/app/site/tags/services/tag-repository.service.ts
+++ b/client/src/app/site/tags/services/tag-repository.service.ts
@@ -5,6 +5,7 @@ import { DataSendService } from '../../../core/services/data-send.service';
 import { DataStoreService } from '../../../core/services/data-store.service';
 import { BaseRepository } from '../../base/base-repository';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository Services for Tags
@@ -26,8 +27,12 @@ export class TagRepositoryService extends BaseRepository<ViewTag, Tag> {
      * Handles CRUD using an observer to the DataStore
      * @param DataSend
      */
-    public constructor(protected DS: DataStoreService, private dataSend: DataSendService) {
-        super(DS, Tag);
+    public constructor(
+        protected DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService
+    ) {
+        super(DS, mapperService, Tag);
     }
 
     protected createViewModel(tag: Tag): ViewTag {
diff --git a/client/src/app/site/users/services/group-repository.service.ts b/client/src/app/site/users/services/group-repository.service.ts
index a3c3c91a2..9ea9b17a8 100644
--- a/client/src/app/site/users/services/group-repository.service.ts
+++ b/client/src/app/site/users/services/group-repository.service.ts
@@ -7,6 +7,7 @@ import { DataStoreService } from '../../../core/services/data-store.service';
 import { DataSendService } from '../../../core/services/data-send.service';
 import { ConstantsService } from '../../../core/services/constants.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Set rules to define the shape of an app permission
@@ -35,8 +36,13 @@ export class GroupRepositoryService extends BaseRepository<ViewGroup, Group> {
      * @param DS Store
      * @param dataSend Sending Data
      */
-    public constructor(DS: DataStoreService, private dataSend: DataSendService, private constants: ConstantsService) {
-        super(DS, Group);
+    public constructor(
+        DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService,
+        private constants: ConstantsService
+    ) {
+        super(DS, mapperService, Group);
         this.sortPermsPerApp();
     }
 
diff --git a/client/src/app/site/users/services/user-repository.service.ts b/client/src/app/site/users/services/user-repository.service.ts
index 401d92163..2153d2be7 100644
--- a/client/src/app/site/users/services/user-repository.service.ts
+++ b/client/src/app/site/users/services/user-repository.service.ts
@@ -7,6 +7,7 @@ import { Group } from '../../../shared/models/users/group';
 import { DataStoreService } from '../../../core/services/data-store.service';
 import { DataSendService } from '../../../core/services/data-send.service';
 import { Identifiable } from '../../../shared/models/base/identifiable';
+import { CollectionStringModelMapperService } from '../../../core/services/collectionStringModelMapper.service';
 
 /**
  * Repository service for users
@@ -20,8 +21,12 @@ export class UserRepositoryService extends BaseRepository<ViewUser, User> {
     /**
      * Constructor calls the parent constructor
      */
-    public constructor(DS: DataStoreService, private dataSend: DataSendService) {
-        super(DS, User, [Group]);
+    public constructor(
+        DS: DataStoreService,
+        mapperService: CollectionStringModelMapperService,
+        private dataSend: DataSendService
+    ) {
+        super(DS, mapperService, User, [Group]);
     }
 
     /**