diff --git a/webapp/mixins/internalPageMixins.js b/webapp/mixins/internalPageMixins.js
index b5ffe62d4..b2443a263 100644
--- a/webapp/mixins/internalPageMixins.js
+++ b/webapp/mixins/internalPageMixins.js
@@ -11,7 +11,10 @@ export function internalPageMixins(pageParams) {
     },
     created() {
       if (!this.pageParams.isInternalPage) {
-        window.location.href = this.pageParams.externalLink
+        // to avoid possible errors, because 'window' is only defined on browser side but not in NodeJS on client side. check for 'typeof window' is neccessary, because if it's not defined at all you can't check for 'window !== undefined' without the same error 'window is undefined'
+        if (typeof window !== 'undefined') {
+          window.location.href = this.pageParams.externalLink
+        }
       }
     },
   }