do not throw error if custom property doesn't exist.

process/DataCaching_lib/process.js

@@ -66,8 +66,14 @@ CachedData.prototype.load = function(pDataCallbackFunction)
     //currently it's not possible to cache the data within the serer-context, so instead the Data-function is called everytime 
     if (this.runningOnServer)
         cachingEnabled = false;
-    else if (JSON.parse(project.getInstanceConfigValue("custom.dataCaching.client.forceDisable")) == true)
-        cachingEnabled = false;
+    else 
+    {
+        try 
+        {
+            if (JSON.parse(project.getInstanceConfigValue("custom.dataCaching.client.forceDisable")) == true)
+                cachingEnabled = false;
+        } catch (ex) {/* ignore */}
+    }
 
     if (!cachingEnabled)
         return pDataCallbackFunction.call(this, this.keepPerLanguage, this.locale);