Hi All,

I have just encountered a very frustrating issue;

As random as it could possibly happen, this morning all of our installed SharePoint Store apps have broken.

They still display correctly through their web\app parts, but the moment the header is clicked, we receive the following error;

Entries in the ULS Logs say much the same;

Application error when access /ImportantMessages/Pages/Default.aspx, Error=Accessing referenced file https://app-25d238edb9176b.**.com/_catalogs/masterpage/**MasterPage.master from https://app-25d238edb9176b.**.com/ImportantMessages/Pages/Default.aspx?SPHostUrl=https://intranet.**.com.au&SPLanguage=en-AU&SPClientTag=14&SPProductNumber=15.0.4420.1017&SPAppWebUrl=https://app-25d238edb9176b.**.com/ImportantMessages is not allowed because the reference is outside of the App Web.

I have done the following in an attempt to correct the issue;

• Re-read through the steps on configuring the app domain
• Reinstalled the Apps
  
• Ran an IISReset

Any help would be much appreciated.

Pete