Basically what has happened is my boss upgraded Quickbooks from 13.0 to 14.0 and broke the RemoteApp for 13.0 (obviously). The upgrade process involves installing the new version without removing the old so it can copy/move files to the new installation folder.
So I removed the old RemoteApp entry for 13.0 and published a new RemoteApp for the new version and emailed myself the rdp file to test.
On testing, I get the error: "The program Quickbooks Enterprise Solutions - Contractor Edition 13.0 was not found. For assistance, contact your system administrator."
I don't understand why it's trying to launch v13.0 when the remoteapp listing in RemoteApp Manager is clearly pointing to the v14.0 installation path and executable.
FWIW the executable name has not changed from 13.0 to 14.0 (of course) but is at a different path altogether.