diff --git a/Build/Sources/TypeScript/backend/Resources/Public/TypeScript/WindowManager.ts b/Build/Sources/TypeScript/backend/Resources/Public/TypeScript/WindowManager.ts
index bf437deafcd84cb3aa47b1b0e011c1b8751055c7..bbba5b524dc64b11f0b1db84caba5981a7011ce3 100644
--- a/Build/Sources/TypeScript/backend/Resources/Public/TypeScript/WindowManager.ts
+++ b/Build/Sources/TypeScript/backend/Resources/Public/TypeScript/WindowManager.ts
@@ -37,9 +37,16 @@ class WindowManager {
       switchFocus = true;
     }
     const existingWindow = this.windows[windowName] ?? window.open('', windowName, windowFeatures);
-    // Note: `existingWindow instanceof Window` wouldn't work here as `existingWindow` is from a another browser context/window.
-    // see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof#instanceof_and_multiple_contexts_e.g._frames_or_windows
-    const isInstanceOfWindow = existingWindow.constructor.name === 'Window';
+    let isInstanceOfWindow = false;
+    try {
+      // Note: `existingWindow instanceof Window` wouldn't work here as `existingWindow` is from another browser context/window.
+      // Note: this will still fail if `existingWindow` points to a cross-origin frame
+      // see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/instanceof#instanceof_and_multiple_realms
+      isInstanceOfWindow = existingWindow.constructor.name === 'Window';
+    } catch (DOMException) {
+      // Intended fall-thru
+      // DOMException is thrown if existingWindow points to a cross-origin frame which we're not allowed to access
+    }
     const existingUri = isInstanceOfWindow && !existingWindow.closed ? existingWindow.location.href : null;
 
     if (Utility.urlsPointToSameServerSideResource(uri, existingUri)) {
diff --git a/typo3/sysext/backend/Resources/Public/JavaScript/WindowManager.js b/typo3/sysext/backend/Resources/Public/JavaScript/WindowManager.js
index 89db29243eed6738e3b5e8684d66ec794649ecb8..8395f1b7e3f1db3ead72720c85d11582f7c0225d 100644
--- a/typo3/sysext/backend/Resources/Public/JavaScript/WindowManager.js
+++ b/typo3/sysext/backend/Resources/Public/JavaScript/WindowManager.js
@@ -10,4 +10,4 @@
  *
  * The TYPO3 project - inspiring people to share!
  */
-var __importDefault=this&&this.__importDefault||function(n){return n&&n.__esModule?n:{default:n}};define(["require","exports","TYPO3/CMS/Backend/Utility"],(function(n,o,e){"use strict";e=__importDefault(e);class t{constructor(){this.windows={},this.open=(...n)=>this._localOpen.apply(this,n),this.globalOpen=(...n)=>this._localOpen.apply(this,n),this.localOpen=(n,o,e="newTYPO3frontendWindow",t="")=>this._localOpen(n,o,e,t)}_localOpen(n,o,t="newTYPO3frontendWindow",i=""){var l;if(!n)return null;null===o?o=!window.opener:void 0===o&&(o=!0);const r=null!==(l=this.windows[t])&&void 0!==l?l:window.open("",t,i),s="Window"===r.constructor.name&&!r.closed?r.location.href:null;if(e.default.urlsPointToSameServerSideResource(n,s))return r.location.replace(n),r.location.reload(),r;const a=window.open(n,t,i);return this.windows[t]=a,o&&a.focus(),a}}const i=new t;return top.TYPO3.WindowManager||(top.document===window.document?top.TYPO3.WindowManager=i:top.TYPO3.WindowManager=new t),i}));
\ No newline at end of file
+var __importDefault=this&&this.__importDefault||function(n){return n&&n.__esModule?n:{default:n}};define(["require","exports","TYPO3/CMS/Backend/Utility"],(function(n,o,t){"use strict";t=__importDefault(t);class e{constructor(){this.windows={},this.open=(...n)=>this._localOpen.apply(this,n),this.globalOpen=(...n)=>this._localOpen.apply(this,n),this.localOpen=(n,o,t="newTYPO3frontendWindow",e="")=>this._localOpen(n,o,t,e)}_localOpen(n,o,e="newTYPO3frontendWindow",i=""){var l;if(!n)return null;null===o?o=!window.opener:void 0===o&&(o=!0);const r=null!==(l=this.windows[e])&&void 0!==l?l:window.open("",e,i);let s=!1;try{s="Window"===r.constructor.name}catch(n){}const a=s&&!r.closed?r.location.href:null;if(t.default.urlsPointToSameServerSideResource(n,a))return r.location.replace(n),r.location.reload(),r;const c=window.open(n,e,i);return this.windows[e]=c,o&&c.focus(),c}}const i=new e;return top.TYPO3.WindowManager||(top.document===window.document?top.TYPO3.WindowManager=i:top.TYPO3.WindowManager=new e),i}));
\ No newline at end of file