diff --git a/dmp-frontend/src/app/dmps/editor/dmp-editor.component.html b/dmp-frontend/src/app/dmps/editor/dmp-editor.component.html
index f2ed12c21..3efcfbe34 100644
--- a/dmp-frontend/src/app/dmps/editor/dmp-editor.component.html
+++ b/dmp-frontend/src/app/dmps/editor/dmp-editor.component.html
@@ -67,7 +67,7 @@
                     <mat-progress-bar [style.height.px]="2" *ngIf="filteringResearchersAsync" mode="indeterminate"></mat-progress-bar>
                 </td-chips>
 
-                <mat-list *ngIf="associatedUsers.length" role="list">
+                <mat-list *ngIf="associatedUsers?.length" role="list">
                         <h3 mat-subheader>Associated Users</h3>                
                         <mat-list-item role="listitem" *ngFor="let user of associatedUsers">
                         <mat-icon mat-list-icon>person</mat-icon>
diff --git a/dmp-frontend/src/app/invitation/invitation.component.ts b/dmp-frontend/src/app/invitation/invitation.component.ts
index 32527c36f..5e98b9935 100644
--- a/dmp-frontend/src/app/invitation/invitation.component.ts
+++ b/dmp-frontend/src/app/invitation/invitation.component.ts
@@ -7,7 +7,7 @@ import { User } from '../models/invitation/User';
 import { Component, OnInit, Inject } from "@angular/core";
 import { FormGroup } from '@angular/forms';
 import { Params, ActivatedRoute, Router } from '@angular/router';
-import { MAT_DIALOG_DATA } from '@angular/material';
+import { MAT_DIALOG_DATA, MatDialogRef } from '@angular/material';
 
 @Component({
     selector: 'app-invitation-component',
@@ -27,6 +27,7 @@ export class InvitationComponent implements OnInit {
         private invitationService: InvitationService,
         private route: ActivatedRoute,
         public router: Router,
+        public dialogRef: MatDialogRef<InvitationComponent>,        
         @Inject(MAT_DIALOG_DATA) public data: any
     ) { }
 
@@ -38,7 +39,9 @@ export class InvitationComponent implements OnInit {
 
 
     send(value: any) {
-        this.invitationService.inviteUsers(this.formGroup.value).subscribe();
+        this.invitationService.inviteUsers(this.formGroup.value).subscribe(
+            null,null,()=>this.dialogRef.close()
+        );
     }
 
     filterUsers(value: string): void {
diff --git a/dmp-frontend/src/app/utilities/cite-http-service-module/base-http.service.ts b/dmp-frontend/src/app/utilities/cite-http-service-module/base-http.service.ts
index 588a1698e..31ca4bf26 100644
--- a/dmp-frontend/src/app/utilities/cite-http-service-module/base-http.service.ts
+++ b/dmp-frontend/src/app/utilities/cite-http-service-module/base-http.service.ts
@@ -1,3 +1,4 @@
+import { Message } from '@angular/compiler/src/i18n/i18n_ast';
 import { ApiMessageCode } from '../types/ApiMessageCode';
 import { Injectable } from '@angular/core';
 import { Http, RequestOptions, Response, Headers } from '@angular/http';
@@ -80,11 +81,27 @@ export class BaseHttpService {
 					//this.notification.httpError(error);
 					return Observable.of<T>();
 				} else {
-					return Observable.throw(errorResponse);
+					let error:any = errorResponse.error
+					if(error.statusCode == ApiMessageCode.ERROR_MESSAGE){
+						this.snackBar.openFromComponent(SnackBarNotificationComponent, {
+							data: { message: error.message, language: null },
+							duration: 3000,
+							extraClasses: ['snackbar-warning']
+						})
+						return Observable.throw(errorResponse);						
+					}
+					else{
+						this.snackBar.openFromComponent(SnackBarNotificationComponent, {
+							data: { message: 'GENERAL.ERRORS.HTTP-REQUEST-ERROR', language: this.language },
+							duration: 3000,
+							extraClasses: ['snackbar-warning']
+						})
+						return Observable.throw(errorResponse);	
+					}
 				}
 			})
 			.map(response => {
-				if (response.statusCode = ApiMessageCode.SUCCESS_MESSAGE) {
+				if (response.statusCode == ApiMessageCode.SUCCESS_MESSAGE) {
 					//throw new Error('Request failed');
 					this.snackBar.openFromComponent(SnackBarNotificationComponent, {
 						data: { message: response.message, language: null },
@@ -94,7 +111,10 @@ export class BaseHttpService {
 					return response.payload;
 					
 				}
-				else {
+				else if(response.statusCode == ApiMessageCode.NO_MESSAGE){
+					return response.payload;
+				}
+				else{
 					return response.payload;
 				}
 			});
diff --git a/dmp-frontend/src/assets/lang/en.json b/dmp-frontend/src/assets/lang/en.json
index 6111b9e86..c6b290fa4 100644
--- a/dmp-frontend/src/assets/lang/en.json
+++ b/dmp-frontend/src/assets/lang/en.json
@@ -16,6 +16,9 @@
             "SUCCESSFUL-LOGOUT": "Successful Logout",
             "UNSUCCESSFUL-LOGOUT": "Unsuccessful Logout",
             "UNSUCCESSFUL-LOGIN": "Unsuccessful Login"
+        },
+        "ERROR":{
+            "HTTP-REQUEST-ERROR":"AN Unexpected Error Has Occured"
         }
     },
     "NAV-BAR": {