diff --git a/alfa-client/libs/collaboration-shared/src/lib/collaboration.service.ts b/alfa-client/libs/collaboration-shared/src/lib/collaboration.service.ts
index 736d0cb47f6cd6ed943688a389a6f8f5e9acb388..f210a1133df3293f5bfa9da2bdd97fe033af1f6c 100644
--- a/alfa-client/libs/collaboration-shared/src/lib/collaboration.service.ts
+++ b/alfa-client/libs/collaboration-shared/src/lib/collaboration.service.ts
@@ -42,7 +42,7 @@ export class CollaborationService {
         order: CommandOrder.CREATE_COLLABORATION_REQUEST,
         body: collaborationRequest,
       },
-      snackBarMessage: 'Die Zuarbeit wurde angefragt',
+      snackBarMessage: 'Die Zuarbeit wurde angefragt.',
     });
   }
 }
diff --git a/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.spec.ts b/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.spec.ts
index 2099588d498d90965f498e9c9c8a1bce56d9bce5..f264006658fe044ac57ad9a2926427046ba6f029 100644
--- a/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.spec.ts
+++ b/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.spec.ts
@@ -99,4 +99,12 @@ describe('OrganisationsEinheitService', () => {
       expect(searchService.selectResult).toHaveBeenCalledWith(organisationsEinheitResource);
     });
   });
+
+  describe('clear selected result', () => {
+    it('should call service', () => {
+      service.clearSelectedResult();
+
+      expect(searchService.clearSelectedResult).toHaveBeenCalled();
+    });
+  });
 });
diff --git a/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.ts b/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.ts
index f4fadaf317dfd2bc7bf9103e8bd4d953613c21aa..495c115446391b8d126feef91bc6b02ad9c24134 100644
--- a/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.ts
+++ b/alfa-client/libs/collaboration-shared/src/lib/organisations-einheit.service.ts
@@ -30,4 +30,8 @@ export class OrganisationsEinheitService {
   public selectSearchResult(organisationsEinheitResource: OrganisationsEinheitResource): void {
     this.searchService.selectResult(organisationsEinheitResource);
   }
+
+  public clearSelectedResult(): void {
+    this.searchService.clearSelectedResult();
+  }
 }
diff --git a/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.spec.ts b/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.spec.ts
index 85649462f34ddd362382333feed07cf10693ed88..a5e6e9e22dc4c22f174f59115b1bb954d1addaf3 100644
--- a/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.spec.ts
+++ b/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.spec.ts
@@ -155,4 +155,12 @@ describe('CollaborationInVorgangContainerComponent', () => {
       expect(service.hideRequestForm).toHaveBeenCalled();
     });
   });
+
+  describe('ngOnDestroy', () => {
+    it('should call service to clear selected result', () => {
+      component.ngOnDestroy();
+
+      expect(organisationsEinheitSearchService.clearSelectedResult).toHaveBeenCalled();
+    });
+  });
 });
diff --git a/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.ts b/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.ts
index 63127377e2c066b9a8eedaa7e2ca7b58c74ba8fa..50c5d04bcffdbd5cd7171a14c5f696839b7447ea 100644
--- a/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.ts
+++ b/alfa-client/libs/collaboration/src/lib/collaboration-in-vorgang-container/collaboration-in-vorgang-container.component.ts
@@ -1,6 +1,6 @@
 import { OrganisationsEinheitResource } from '@alfa-client/collaboration-shared';
 import { StateResource } from '@alfa-client/tech-shared';
-import { Component, OnInit } from '@angular/core';
+import { Component, OnDestroy, OnInit } from '@angular/core';
 import { CollaborationListResource } from 'libs/collaboration-shared/src/lib/collaboration.model';
 import { CollaborationService } from 'libs/collaboration-shared/src/lib/collaboration.service';
 import { OrganisationsEinheitResourceSearchService } from 'libs/collaboration-shared/src/lib/organisations-einheit-resource-search.service';
@@ -10,7 +10,7 @@ import { Observable } from 'rxjs';
   selector: 'alfa-collaboration-in-vorgang-container',
   templateUrl: './collaboration-in-vorgang-container.component.html',
 })
-export class CollaborationInVorgangContainerComponent implements OnInit {
+export class CollaborationInVorgangContainerComponent implements OnInit, OnDestroy {
   public collaborationStateListResource$: Observable<StateResource<CollaborationListResource>>;
   public isRequestFormVisible$: Observable<boolean>;
   public selectedOrganisationsEinheit$: Observable<OrganisationsEinheitResource>;
@@ -33,4 +33,8 @@ export class CollaborationInVorgangContainerComponent implements OnInit {
   public hideRequestForm(): void {
     this.service.hideRequestForm();
   }
+
+  ngOnDestroy(): void {
+    this.searchService.clearSelectedResult();
+  }
 }
diff --git a/alfa-client/libs/command-shared/src/lib/+state/command.effects.spec.ts b/alfa-client/libs/command-shared/src/lib/+state/command.effects.spec.ts
index c461fcffe58c1bff6b679c9175b70af066484b98..2ee1199a7ec572ca5c33e21ed788c098f2b95015 100644
--- a/alfa-client/libs/command-shared/src/lib/+state/command.effects.spec.ts
+++ b/alfa-client/libs/command-shared/src/lib/+state/command.effects.spec.ts
@@ -1,4 +1,3 @@
-import { TestBed } from '@angular/core/testing';
 import {
   ApiError,
   ApiErrorAction,
@@ -7,6 +6,7 @@ import {
 } from '@alfa-client/tech-shared';
 import { Mock, mock } from '@alfa-client/test-utils';
 import { SnackBarService } from '@alfa-client/ui';
+import { TestBed } from '@angular/core/testing';
 import { provideMockActions } from '@ngrx/effects/testing';
 import { Action, Store, createAction, props } from '@ngrx/store';
 import { TypedAction } from '@ngrx/store/src/models';
@@ -26,7 +26,12 @@ import { CommandLinkRel } from '../command.linkrel';
 import { CREATE_COMMAND_MESSAGE_BY_ORDER, CommandErrorMessage } from '../command.message';
 import { CommandListResource, CommandResource, CreateCommandProps } from '../command.model';
 import { CommandRepository } from '../command.repository';
-import { CommandProps, LoadCommandListSuccessProps, createCommandFailure } from './command.actions';
+import {
+  CommandProps,
+  LoadCommandListSuccessProps,
+  SnackBarProps,
+  createCommandFailure,
+} from './command.actions';
 import { CommandEffects } from './command.effects';
 
 import * as CommandActions from './command.actions';
@@ -35,13 +40,17 @@ describe('CommandEffects', () => {
   let actions: Observable<Action>;
   let effects: CommandEffects;
 
-  const repository: Mock<CommandRepository> = mock(CommandRepository);
-  const snackBarService: Mock<SnackBarService> = mock(SnackBarService);
-  const store: Mock<SnackBarService> = mock(SnackBarService);
+  let repository: Mock<CommandRepository>;
+  let snackBarService: Mock<SnackBarService>;
+  let store: Mock<Store>;
 
   let testScheduler: TestScheduler;
 
   beforeEach(() => {
+    repository = mock(CommandRepository);
+    snackBarService = mock(SnackBarService);
+    store = mock(Store);
+
     testScheduler = new TestScheduler((actual, expected) => expect(actual).toEqual(expected));
 
     TestBed.configureTestingModule({
@@ -374,7 +383,8 @@ describe('CommandEffects', () => {
     const createCommandProps: CreateCommandProps = createCreateCommandProps();
     const command: CommandResource = createCommandResource();
 
-    it('should show snackBar on existing snackBarMessage', () => {
+    it('should call handle snackbar by command', () => {
+      effects.handleSnackbarByCommand = jest.fn();
       const showSnackbarAction: TypedAction<string> = CommandActions.showSnackbar({
         createCommandProps,
         command,
@@ -383,6 +393,19 @@ describe('CommandEffects', () => {
       actions = of(showSnackbarAction);
       effects.showSnackbar$.subscribe();
 
+      expect(effects.handleSnackbarByCommand).toHaveBeenCalled();
+    });
+  });
+
+  describe('handle snackbar by command', () => {
+    const createCommandProps: CreateCommandProps = createCreateCommandProps();
+    const command: CommandResource = createCommandResource();
+
+    it('should show snackBar on existing snackBarMessage', () => {
+      const snackBarProps: SnackBarProps = { createCommandProps, command };
+
+      effects.handleSnackbarByCommand(snackBarProps);
+
       expect(snackBarService.show).toHaveBeenCalledWith(
         command,
         createCommandProps.snackBarMessage,
@@ -390,13 +413,12 @@ describe('CommandEffects', () => {
     });
 
     it('should show snackBar on undefined snackBarMessage', () => {
-      const showSnackbarAction: TypedAction<string> = CommandActions.showSnackbar({
+      const snackBarProps: SnackBarProps = {
         createCommandProps: { ...createCommandProps, snackBarMessage: undefined },
         command,
-      });
+      };
 
-      actions = of(showSnackbarAction);
-      effects.showSnackbar$.subscribe();
+      effects.handleSnackbarByCommand(snackBarProps);
 
       expect(snackBarService.show).toHaveBeenCalledWith(
         command,
@@ -404,16 +426,24 @@ describe('CommandEffects', () => {
       );
     });
 
-    //Faellt um, wenn man ihn mit den anderen Tests zusammen laufen laesst
-    it.skip('FIXME should NOT show snackBar on empty snackBarMessage', () => {
-      const showSnackbarAction: TypedAction<string> = CommandActions.showSnackbar({
+    it('should NOT show snackBar on empty snackBarMessage', () => {
+      const snackBarProps: SnackBarProps = {
         createCommandProps: { ...createCommandProps, snackBarMessage: EMPTY_STRING },
         command,
-      });
-      snackBarService.show.mockClear();
+      };
 
-      effects.showSnackbar$.subscribe();
-      actions = of(showSnackbarAction);
+      effects.handleSnackbarByCommand(snackBarProps);
+
+      expect(snackBarService.show).not.toHaveBeenCalled();
+    });
+
+    it('should NOT show snackBar on existing error message', () => {
+      const snackBarProps: SnackBarProps = {
+        createCommandProps,
+        command: { ...command, errorMessage: 'dummyErrorMessage' },
+      };
+
+      effects.handleSnackbarByCommand(snackBarProps);
 
       expect(snackBarService.show).not.toHaveBeenCalled();
     });
diff --git a/alfa-client/libs/command-shared/src/lib/+state/command.effects.ts b/alfa-client/libs/command-shared/src/lib/+state/command.effects.ts
index 3d7151381f57a1c9843bf17179f320bd3c28022c..76c42d3899bc776736f109e5af66d73cccd23aa1 100644
--- a/alfa-client/libs/command-shared/src/lib/+state/command.effects.ts
+++ b/alfa-client/libs/command-shared/src/lib/+state/command.effects.ts
@@ -1,14 +1,21 @@
-import { Injectable } from '@angular/core';
+import { EMPTY_STRING } from '@alfa-client/tech-shared';
 import { SnackBarService } from '@alfa-client/ui';
+import { Injectable } from '@angular/core';
 import { Actions, createEffect, ofType } from '@ngrx/effects';
 import { Store } from '@ngrx/store';
 import { TypedAction } from '@ngrx/store/src/models';
+import { isEmpty, isEqual, isUndefined } from 'lodash-es';
 import { of } from 'rxjs';
 import { catchError, delay, map, mergeMap, switchMap, tap } from 'rxjs/operators';
 import { COMMAND_ERROR_MESSAGES, CREATE_COMMAND_MESSAGE_BY_ORDER } from '../command.message';
 import { CommandListResource, CommandResource, CreateCommandProps } from '../command.model';
 import { CommandRepository } from '../command.repository';
-import { hasCommandError, isConcurrentModification, isPending, isRevokeable } from '../command.util';
+import {
+  hasCommandError,
+  isConcurrentModification,
+  isPending,
+  isRevokeable,
+} from '../command.util';
 import {
   CommandProps,
   LoadCommandListProps,
@@ -27,8 +34,6 @@ import {
   showRevokeSnackbar,
   showSnackbar,
 } from './command.actions';
-import { isEqual, isUndefined } from 'lodash-es';
-import { EMPTY_STRING } from '@alfa-client/tech-shared';
 
 @Injectable()
 export class CommandEffects {
@@ -99,6 +104,8 @@ export class CommandEffects {
     }
     if (hasCommandError(command) && isConcurrentModification(command.errorMessage)) {
       this.showError(command);
+      //FIXME Anstelle der createCommandSucess Action sollte eine createCommandFailure Action geworfen werden.
+      //Hierzu muss ein HttpErrorResponse für die errorMessage definieren werden
       return [createCommandSuccess({ command }), publishConcurrentModificationAction()];
     }
     return [createCommandSuccess({ command }), showSnackbar({ createCommandProps, command })];
@@ -131,15 +138,20 @@ export class CommandEffects {
     () =>
       this.actions$.pipe(
         ofType(showSnackbar),
-        tap((props: SnackBarProps) => {
-          if (!isEqual(props.createCommandProps.snackBarMessage, EMPTY_STRING)) {
-            this.snackbarService.show(props.command, this.getSnackBarMessage(props));
-          }
-        }),
+        tap((props: SnackBarProps) => this.handleSnackbarByCommand(props)),
       ),
     { dispatch: false },
   );
 
+  handleSnackbarByCommand(props: SnackBarProps): void {
+    if (
+      !isEqual(props.createCommandProps.snackBarMessage, EMPTY_STRING) &&
+      isEmpty(props.command.errorMessage)
+    ) {
+      this.snackbarService.show(props.command, this.getSnackBarMessage(props));
+    }
+  }
+
   private getSnackBarMessage(props: SnackBarProps): string {
     return isUndefined(props.createCommandProps.snackBarMessage) ?
         CREATE_COMMAND_MESSAGE_BY_ORDER[props.command.order]
diff --git a/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.spec.ts b/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.spec.ts
index a4873730938d80aa0efe333f7177aca4e2e4ff28..eef4a6cad0cd8c46e932d45a93b11eab29005b62 100644
--- a/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.spec.ts
+++ b/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.spec.ts
@@ -23,7 +23,7 @@
  */
 import { getEmbeddedResource } from '@ngxp/rest';
 import { DummyListLinkRel } from 'libs/tech-shared/test/dummy';
-import { createDummyListResource } from 'libs/tech-shared/test/resource';
+import { createDummyListResource, toResource } from 'libs/tech-shared/test/resource';
 import { ListResource } from '../resource/resource.util';
 import { EMPTY_ARRAY } from '../tech.util';
 import { ToEmbeddedResourcesPipe } from './to-embedded-resource.pipe';
@@ -55,5 +55,11 @@ describe('ToEmbeddedResourcesPipe', () => {
 
       expect(result).toBe(EMPTY_ARRAY);
     });
+
+    it('should return empty array non existing resources', () => {
+      const result: unknown[] = pipe.transform(toResource({}), DummyListLinkRel.LIST);
+
+      expect(result).toBe(EMPTY_ARRAY);
+    });
   });
 });
diff --git a/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.ts b/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.ts
index 77e51945183b3b392c2b3d49647af0bf4a0e02ea..f310e40a994c86031869c1137adf3a3387864b38 100644
--- a/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.ts
+++ b/alfa-client/libs/tech-shared/src/lib/pipe/to-embedded-resource.pipe.ts
@@ -23,7 +23,7 @@
  */
 import { Pipe, PipeTransform } from '@angular/core';
 import { Resource, getEmbeddedResource } from '@ngxp/rest';
-import { isNil } from 'lodash-es';
+import { isNil, isNull } from 'lodash-es';
 import { LinkRelationName } from '../resource/resource.model';
 import { ListResource } from '../resource/resource.util';
 import { EMPTY_ARRAY } from '../tech.util';
@@ -32,6 +32,7 @@ import { EMPTY_ARRAY } from '../tech.util';
 export class ToEmbeddedResourcesPipe implements PipeTransform {
   transform(listResource: ListResource, linkRel: LinkRelationName): Resource[] {
     if (isNil(listResource) || isNil(linkRel)) return EMPTY_ARRAY;
-    return getEmbeddedResource(listResource, linkRel);
+    const embeddedReources: Resource[] = getEmbeddedResource(listResource, linkRel);
+    return isNull(embeddedReources) ? EMPTY_ARRAY : embeddedReources;
   }
 }
diff --git a/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.spec.ts b/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.spec.ts
index acbd45df651fd4343be7601e8a9886850f133f0e..1c1d30cbcd83ef02da378247d4e2792ff750d3a0 100644
--- a/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.spec.ts
+++ b/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.spec.ts
@@ -191,4 +191,16 @@ describe('ResourceSearchService', () => {
       expect(service.selectedResource.value).toEqual(dummyResource);
     });
   });
+
+  describe('clear select result', () => {
+    const dummyResource: Resource = createDummyResource();
+
+    it('should update selected resource to null', () => {
+      service.selectedResource.next(dummyResource);
+
+      service.clearSelectedResult();
+
+      expect(service.selectedResource.value).toBeNull();
+    });
+  });
 });
diff --git a/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.ts b/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.ts
index d23b4be986f9a8fb880e582c5925f525459bf3dc..f8e52663e186ba7c2ebe4b8d6bec0dd593163e3a 100644
--- a/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.ts
+++ b/alfa-client/libs/tech-shared/src/lib/resource/resource-search.service.ts
@@ -98,4 +98,8 @@ export class ResourceSearchService<
   public selectResult(selected: I): void {
     this.selectedResource.next(selected);
   }
+
+  public clearSelectedResult(): void {
+    this.selectedResource.next(null);
+  }
 }
diff --git a/pom.xml b/pom.xml
index bac9e0e473b07a7e6bbc10f857de168643db407e..a824ac03c6c5b1db540c09c85bb3cb6fb6b694b6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -32,7 +32,7 @@
 	<parent>
 		<groupId>de.ozgcloud.common</groupId>
 		<artifactId>ozgcloud-common-parent</artifactId>
-		<version>4.4.0-SNAPSHOT</version>
+		<version>4.3.2</version>
 	</parent>
 
 	<groupId>de.ozgcloud.alfa</groupId>