diff --git a/landingPages/dataProvider/dataProvider.component.ts b/landingPages/dataProvider/dataProvider.component.ts
index 7b358153..2b4d1290 100644
--- a/landingPages/dataProvider/dataProvider.component.ts
+++ b/landingPages/dataProvider/dataProvider.component.ts
@@ -1,4 +1,4 @@
-import {ChangeDetectorRef, Component, ElementRef, HostListener, Input, ViewChild} from '@angular/core';
+import {ChangeDetectorRef, Component, ElementRef, Input, ViewChild} from '@angular/core';
 import {ActivatedRoute, Router} from '@angular/router';
 import {Meta, Title} from '@angular/platform-browser';
 
@@ -26,7 +26,6 @@ import {ResultPreview} from "../../utils/result-preview/result-preview";
 import {IndexInfoService} from "../../utils/indexInfo.service";
 import {properties} from "../../../../environments/environment";
 import {Subscriber, Subscription, zip} from "rxjs";
-import {TabComponent} from "../../utils/tabs/tab.component";
 import {OpenaireEntities} from "../../utils/properties/searchFields";
 import {MetricsService} from '../../services/metrics.service';
 import {NumberUtils} from '../../utils/number-utils.class';
@@ -358,7 +357,8 @@ export class DataProviderComponent {
     this.subscriptions.forEach(subscription => {
       if (subscription instanceof Subscriber) {
         subscription.unsubscribe();
-      } else if (subscription instanceof (ResizeObserver || IntersectionObserver)) {
+      } else if ((typeof ResizeObserver != 'undefined' && subscription instanceof ResizeObserver) ||
+          (typeof IntersectionObserver != 'undefined' && subscription instanceof IntersectionObserver)) {
         subscription.disconnect();
       }
     });
diff --git a/landingPages/organization/organization.component.ts b/landingPages/organization/organization.component.ts
index 25c88990..26330d41 100644
--- a/landingPages/organization/organization.component.ts
+++ b/landingPages/organization/organization.component.ts
@@ -280,7 +280,8 @@ export class OrganizationComponent {
     this.subscriptions.forEach(subscription => {
       if (subscription instanceof Subscriber) {
         subscription.unsubscribe();
-      } else if (subscription instanceof (ResizeObserver || IntersectionObserver)) {
+      } else if ((typeof ResizeObserver != 'undefined' && subscription instanceof ResizeObserver) ||
+          (typeof IntersectionObserver != 'undefined' && subscription instanceof IntersectionObserver)) {
         subscription.disconnect();
       }
     });
diff --git a/landingPages/project/project.component.ts b/landingPages/project/project.component.ts
index cf46334d..bc24e86c 100644
--- a/landingPages/project/project.component.ts
+++ b/landingPages/project/project.component.ts
@@ -1,4 +1,4 @@
-import {ChangeDetectorRef, Component, ElementRef, HostListener, Input, ViewChild} from '@angular/core';
+import {ChangeDetectorRef, Component, ElementRef, Input, ViewChild} from '@angular/core';
 import {ActivatedRoute, Router} from '@angular/router';
 import {Meta, Title} from '@angular/platform-browser';
 
@@ -25,7 +25,7 @@ import {StringUtils} from "../../utils/string-utils.class";
 import {ResultPreview} from "../../utils/result-preview/result-preview";
 import {SearchResult} from "../../utils/entities/searchResult";
 import {IndexInfoService} from "../../utils/indexInfo.service";
-import {Subscriber, zip, Subscription} from "rxjs";
+import {Subscriber, Subscription, zip} from "rxjs";
 import {properties} from "../../../../environments/environment";
 import {Option} from "../../sharedComponents/input/input.component";
 import {OpenaireEntities} from "../../utils/properties/searchFields";
@@ -380,7 +380,8 @@ export class ProjectComponent {
     this.subscriptions.forEach(subscription => {
       if (subscription instanceof Subscriber) {
         subscription.unsubscribe();
-      } else if (subscription instanceof (ResizeObserver || IntersectionObserver)) {
+      } else if ((typeof ResizeObserver != 'undefined' && subscription instanceof ResizeObserver) ||
+          (typeof IntersectionObserver != 'undefined' && subscription instanceof IntersectionObserver)) {
         subscription.disconnect();
       }
     });
diff --git a/landingPages/result/resultLanding.component.ts b/landingPages/result/resultLanding.component.ts
index a44acc1d..0f454bee 100644
--- a/landingPages/result/resultLanding.component.ts
+++ b/landingPages/result/resultLanding.component.ts
@@ -1,4 +1,4 @@
-import {ChangeDetectorRef, Component, ElementRef, EventEmitter, HostListener, Input, Output, ViewChild} from '@angular/core';
+import {ChangeDetectorRef, Component, ElementRef, Input, ViewChild} from '@angular/core';
 import {ActivatedRoute, Router} from '@angular/router';
 import {Meta, Title} from '@angular/platform-browser';
 
@@ -18,8 +18,7 @@ import {IndexInfoService} from "../../utils/indexInfo.service";
 import {Identifier, StringUtils} from "../../utils/string-utils.class";
 import {properties} from "../../../../environments/environment";
 import {ISVocabulariesService} from "../../utils/staticAutoComplete/ISVocabularies.service";
-import {forkJoin, Observable, Subscription, zip} from "rxjs";
-import {AnnotationComponent} from "../annotation/annotation.component";
+import {Subscription} from "rxjs";
 import {ParsingFunctions} from "../landing-utils/parsingFunctions.class";
 import {ConnectHelper} from "../../connect/connectHelper";
 import {UserManagementService} from "../../services/user-management.service";
@@ -383,7 +382,8 @@ export class ResultLandingComponent {
         subscription.unsubscribe();
       } else if (subscription instanceof Function) {
         subscription();
-      } else if (subscription instanceof (ResizeObserver || IntersectionObserver)) {
+      } else if ((typeof ResizeObserver != 'undefined' && subscription instanceof ResizeObserver) ||
+          (typeof IntersectionObserver != 'undefined' && subscription instanceof IntersectionObserver)) {
         subscription.disconnect();
       }
     });
diff --git a/utils/modal/full-screen-modal/full-screen-modal.component.ts b/utils/modal/full-screen-modal/full-screen-modal.component.ts
index fe27d429..f3bb60c9 100644
--- a/utils/modal/full-screen-modal/full-screen-modal.component.ts
+++ b/utils/modal/full-screen-modal/full-screen-modal.component.ts
@@ -76,8 +76,6 @@ export class FullScreenModalComponent implements AfterViewInit, OnDestroy {
 	@ViewChild('modal') modal: ElementRef;
   @ViewChild('header') header: ElementRef;
   @ViewChild('body') body: ElementRef;
-  observer: any;
-  headerHeight: number;
   bodyHeight: number;
   private subscriptions: any[] = [];
   
@@ -99,12 +97,13 @@ export class FullScreenModalComponent implements AfterViewInit, OnDestroy {
 
   ngAfterViewInit() {
     if(typeof window !== "undefined") {
-      this.observer = new ResizeObserver(entries => {
+      let observer = new ResizeObserver(entries => {
         for (let entry of entries) {
           this.changeHeight();
         }
       });
-      this.observer.observe(this.header.nativeElement);
+      observer.observe(this.header.nativeElement);
+      this.subscriptions.push(observer);
     }
   }
   
@@ -117,9 +116,6 @@ export class FullScreenModalComponent implements AfterViewInit, OnDestroy {
   }
   
   ngOnDestroy() {
-    if(this.observer && this.observer instanceof ResizeObserver) {
-      this.observer.disconnect();
-    }
     if(typeof document !== "undefined") {
       const element = document.getElementById("modal-container");
       for (let i = element.childNodes.length - 1; i >= 0; --i) {
@@ -132,8 +128,10 @@ export class FullScreenModalComponent implements AfterViewInit, OnDestroy {
     this.subscriptions.forEach(subscription => {
       if(subscription instanceof Subscription) {
         subscription.unsubscribe();
+      } else if(typeof ResizeObserver != 'undefined' && subscription instanceof ResizeObserver) {
+        subscription.disconnect();
       }
-    })
+    });
   }
   
   get isOpen() {