diff --git a/README.md b/README.md
index c3ea043..1695fc8 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ Das Paket liegt danach unter `sharepoint/solution/portal-settings.sppkg`.
 
 ## Installation und Upgrade
 
-1. `portal-settings.sppkg` im App Catalog durch Version `2.1.3.0` ersetzen.
+1. `portal-settings.sppkg` im App Catalog durch Version `2.1.4.0` ersetzen.
 2. PortalSettings im Root Web der Site Collection installieren beziehungsweise aktualisieren.
 3. `expiry-indicator.sppkg` durch Version `2.1.0.0` ersetzen und die App aktualisieren.
 4. `/SitePages/PortalSettings.aspx` mit geleertem Browsercache laden.
diff --git a/config/package-solution.json b/config/package-solution.json
index d268626..b70408c 100644
--- a/config/package-solution.json
+++ b/config/package-solution.json
@@ -3,7 +3,7 @@
   "solution": {
     "name": "portal-settings-client-side-solution",
     "id": "1c98e32d-bb7b-43b7-9625-074d6e4ea286",
-    "version": "2.1.3.0",
+    "version": "2.1.4.0",
     "includeClientSideAssets": true,
     "skipFeatureDeployment": false,
     "features": [
@@ -11,7 +11,7 @@
         "title": "Portal Settings",
         "description": "Provisioniert die zentrale Settings-Seite fuer aktive Portal-Erweiterungen.",
         "id": "57bd9daf-48f9-49e2-aebd-11b15a0b5e93",
-        "version": "2.1.3.0",
+        "version": "2.1.4.0",
         "assets": {
           "elementManifests": [
             "elements-v2.xml"
diff --git a/package-lock.json b/package-lock.json
index b66af31..6668aa9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "portal-settings",
-  "version": "2.1.3",
+  "version": "2.1.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 009e09a..9f89f6c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "portal-settings",
-  "version": "2.1.3",
+  "version": "2.1.4",
   "private": true,
   "main": "lib/index.js",
   "engines": {
diff --git a/sharepoint/assets/PortalSettings.aspx b/sharepoint/assets/PortalSettings.aspx
index 1e44a2e..574b307 100644
--- a/sharepoint/assets/PortalSettings.aspx
+++ b/sharepoint/assets/PortalSettings.aspx
@@ -86,7 +86,7 @@ function postJson(url,payload,onSuccess,onError){try{var digest=getRequestDigest
 function postJsonMerge(url,payload,onSuccess,onError){try{var digest=getRequestDigest();if(!digest){onError('Kein Request Digest gefunden. Laden Sie die Seite neu und versuchen Sie es erneut.');return;}var request=new XMLHttpRequest();request.open('POST',url,true);request.setRequestHeader('Accept','application/json;odata=verbose');request.setRequestHeader('Content-Type','application/json;odata=verbose');request.setRequestHeader('X-RequestDigest',digest);request.setRequestHeader('IF-MATCH','*');request.setRequestHeader('X-HTTP-Method','MERGE');request.onreadystatechange=function(){if(request.readyState!==4){return;}if(request.status>=200&&request.status<300){onSuccess();return;}onError(buildRequestErrorMessage(request));};request.onerror=function(){onError('Netzwerkfehler beim Aktualisieren von '+url);};request.send(JSON.stringify(payload));}catch(error){onError(error.message||String(error));}}
 function getRequestDigest(){var digestField=document.getElementById('__REQUESTDIGEST');return digestField&&digestField.value?digestField.value:'';}
 function getResultArray(payload){if(payload&&payload.d&&Array.isArray(payload.d.results)){return payload.d.results;}if(payload&&Array.isArray(payload.value)){return payload.value;}return [];}
-function normalizeGuid(value){if(typeof value!=='string'){return '';}return value.replace(/[{}]/g,'').toLowerCase();}
+function normalizeGuid(value){if(typeof value!=='string'){return '';}var normalized=value.replace(/[{}]/g,'').toLowerCase();return normalized==='00000000-0000-0000-0000-000000000000'?'':normalized;}
 function buildRequestErrorMessage(request){var message=String(request.status||0);if(request.statusText){message+=' '+request.statusText;}if(request.responseText){try{var payload=JSON.parse(request.responseText);if(payload&&payload.error&&payload.error.message){message+=': '+(payload.error.message.value||payload.error.message);}}catch(ignoreError){}}return message;}
 function getAvailableSolutionKeys(){return Object.keys(SUPPORTED_SOLUTIONS).filter(function(key){return !!state.solutions[key];});}
 function getActionLocationText(info){if(!info||!info.action){return '-';}var scopeLabel=info.scopeLabel?info.scopeLabel+' | ':'';return scopeLabel+(info.action.Location||'ClientSideExtension.ApplicationCustomizer');}
diff --git a/src/assets/PortalSettings.aspx b/src/assets/PortalSettings.aspx
index 1e44a2e..574b307 100644
--- a/src/assets/PortalSettings.aspx
+++ b/src/assets/PortalSettings.aspx
@@ -86,7 +86,7 @@ function postJson(url,payload,onSuccess,onError){try{var digest=getRequestDigest
 function postJsonMerge(url,payload,onSuccess,onError){try{var digest=getRequestDigest();if(!digest){onError('Kein Request Digest gefunden. Laden Sie die Seite neu und versuchen Sie es erneut.');return;}var request=new XMLHttpRequest();request.open('POST',url,true);request.setRequestHeader('Accept','application/json;odata=verbose');request.setRequestHeader('Content-Type','application/json;odata=verbose');request.setRequestHeader('X-RequestDigest',digest);request.setRequestHeader('IF-MATCH','*');request.setRequestHeader('X-HTTP-Method','MERGE');request.onreadystatechange=function(){if(request.readyState!==4){return;}if(request.status>=200&&request.status<300){onSuccess();return;}onError(buildRequestErrorMessage(request));};request.onerror=function(){onError('Netzwerkfehler beim Aktualisieren von '+url);};request.send(JSON.stringify(payload));}catch(error){onError(error.message||String(error));}}
 function getRequestDigest(){var digestField=document.getElementById('__REQUESTDIGEST');return digestField&&digestField.value?digestField.value:'';}
 function getResultArray(payload){if(payload&&payload.d&&Array.isArray(payload.d.results)){return payload.d.results;}if(payload&&Array.isArray(payload.value)){return payload.value;}return [];}
-function normalizeGuid(value){if(typeof value!=='string'){return '';}return value.replace(/[{}]/g,'').toLowerCase();}
+function normalizeGuid(value){if(typeof value!=='string'){return '';}var normalized=value.replace(/[{}]/g,'').toLowerCase();return normalized==='00000000-0000-0000-0000-000000000000'?'':normalized;}
 function buildRequestErrorMessage(request){var message=String(request.status||0);if(request.statusText){message+=' '+request.statusText;}if(request.responseText){try{var payload=JSON.parse(request.responseText);if(payload&&payload.error&&payload.error.message){message+=': '+(payload.error.message.value||payload.error.message);}}catch(ignoreError){}}return message;}
 function getAvailableSolutionKeys(){return Object.keys(SUPPORTED_SOLUTIONS).filter(function(key){return !!state.solutions[key];});}
 function getActionLocationText(info){if(!info||!info.action){return '-';}var scopeLabel=info.scopeLabel?info.scopeLabel+' | ':'';return scopeLabel+(info.action.Location||'ClientSideExtension.ApplicationCustomizer');}