Upgrading StoreFront from 3.6 to 3.9 works fine and when we open the Citrix StoreFront gives an error message:"unable to refresh" with error "A PowerShell SDK execution error occurred with exception thrown at defaultDocument".

Complete the following steps to resolve the issue:

1. Run the PowerShell command on StoreFront Server.
2. Get-STFWebReceiverService, it gives error with "A PowerShell SDK execution error occurred with exception thrown at defaultDocument" 
3. Compare Web.Config file for StoreWeb with Working and Non-working. 
4. There is a "<clear />" entry on web.config file for the defaultdocuments in the web.config file for the Receiver for Web site on non-working server.  
5. -Once we remove the <clear /> from web.config, StoreFront console should work fine.

Problem Cause