Event ID 30016 - Error - Citrix XML Service object was not found: 404 Not found.

When users trying to connect to the XenApp server using Citrix XenApp Online Plug-in see the following error:

"The remote server failed to execute the application launch request. Please contact your administrator for further details."

In the server's event log, under Application, there is this Event ID 30016 error being logged.

"The Citrix XML Service object was not found: 404 Not Found. This message was reported from the XML Service at address http://[server]/scripts/wpnbr.dll [com.citrix.xml.NfuseProtocol.RequestAppData]. The specific Citrix XML Service could not be contacted and has been temporarily removed from the list of active services. [Unique Log ID: _]

Cause: The scripts folder may not be shared out properly or the port is shared with IIS but not configured properly, thus the 404 not found error message.

To resolve this, refer to Citrix Knowledge Article CTX104063.