diff --git a/claims/claim-utils/service/contexts.service.ts b/claims/claim-utils/service/contexts.service.ts
index bac39660..094b47d7 100644
--- a/claims/claim-utils/service/contexts.service.ts
+++ b/claims/claim-utils/service/contexts.service.ts
@@ -11,7 +11,7 @@ export class ContextsService {
   private promise: Promise<any>;
   private sub: Subscription = null;
 
-  constructor(private http: HttpClient ) {
+  constructor(private http: HttpClient=null ) {
   }
 
   ngOnDestroy() {
diff --git a/landingPages/landing-utils/parsingFunctions.class.ts b/landingPages/landing-utils/parsingFunctions.class.ts
index fb3816a0..aa6a6601 100644
--- a/landingPages/landing-utils/parsingFunctions.class.ts
+++ b/landingPages/landing-utils/parsingFunctions.class.ts
@@ -484,8 +484,7 @@ export class ParsingFunctions {
         if (!identifiers.has(pid.classid)) {
           identifiers.set(pid.classid, new Array<string>());
         }
-        
-        identifiers.get(pid.classid).push(pid.content);
+        identifiers.get(pid.classid).push(pid.content+"");
       }
     } else {
       for (let i = 0; i < pid.length; i++) {
@@ -493,7 +492,7 @@ export class ParsingFunctions {
           if (!identifiers.has(pid[i].classid)) {
             identifiers.set(pid[i].classid, new Array<string>());
           }
-          identifiers.get(pid[i].classid).push(pid[i].content);
+          identifiers.get(pid[i].classid).push(pid[i].content+"");
         }
       }
     }
diff --git a/services/searchResearchResults.service.ts b/services/searchResearchResults.service.ts
index 9872d559..dd93c74a 100644
--- a/services/searchResearchResults.service.ts
+++ b/services/searchResearchResults.service.ts
@@ -13,8 +13,8 @@ import {properties} from "../../../environments/environment";
 export class SearchResearchResultsService {
   private sizeOfDescription: number = 270;
   public parsingFunctions: ParsingFunctions = new ParsingFunctions();
-  
-  constructor(private http: HttpClient) {
+
+  constructor(private http: HttpClient=null) {
   }
   
   
@@ -174,9 +174,12 @@ export class SearchResearchResultsService {
   
   parseResults(resultType: string, data: any, properties: EnvProperties): SearchResult[] {
     let results: SearchResult[] = [];
-    
+    if(data == null) {
+      return results;
+    }
+
     let length = Array.isArray(data) ? data.length : 1;
-    
+
     for (let i = 0; i < length; i++) {
       let resData = Array.isArray(data) ? data[i]['result']['metadata']['oaf:entity']['oaf:result'] : data['result']['metadata']['oaf:entity']['oaf:result'];
       
@@ -207,8 +210,8 @@ export class SearchResearchResultsService {
         } else {
           for (let i = 0; i < resData['pid'].length; i++) {
             if (resData['pid'][i].classid == 'doi') {
-              if (resData['pid'][i].content != '' && resData['pid'][i].content != null) {
-                result.DOIs.push(resData['pid'][i].content.replace("https://doi.org/", ""));
+              if (resData['pid'][i].content != '' && resData['pid'][i].content != null && resData['pid'][i].content) {
+                result.DOIs.push((resData['pid'][i].content+"").replace("https://doi.org/", ""));
               }
             }
           }