Currently, if GP Web Services loses connection to its SQL Security store (the dreaded "Handle is Invalid" error), GP Web Services continues to retry indefinitely. The Service is in a halfway state, saying it is “running”, but it will not ever reconnect, nor will it shutdown normally. It generally needs a Server restart to resolve. This error has been reported since at least GP 10. We are on GP 2013 R2. It is not fixed in GP 2016.

• The system cannot find the file specified. (Exception from HRESULT: 0x80070002)
• The handle is invalid. (Exception from HRESULT: 0x80070006 (E_HANDLE))

Reconnect automatically or allow it to close gracefully
The best solution is to reconnect. An alternate would be to have it gracefully close after losing connection. It is the halfway state that really messes things up. Current behavior is that the Service still shows “running” even after the “handle” errors start. A standard Net Stop will not work, and Taskkill is needed to stop it.

• C:\Windows\system32>C:\Windows\system32>Net Stop DynGPWebService
• The service could not be controlled in its present state.

If the “Microsoft Dynamics GP Service Host” service died gracefully, the Windows “Recovery” Services feature could take care of the restart.