some of my clients stop wpkg service with event Id 7039

[konus1]

I have 11 Clients running Windows 8.1 64 bit. Between 15.07.2015 and 25.07.2015 six of them stopped running wpkg. The other five Clients are just running fine. I already tried to find the issue, but I am lost:

There are some entries in den event-log of Windows.
Right after boot, The first warning in system-event log of this clients is event id 7039

"A service process other than the one launched by the Service Control Manager connected when starting the "WPKG Control Service" service. The Service Control Manager launched process %2 and process %3 connected instead.

Note that if this service is configured to start under a debugger, this behavior is expected."

After that I get a warning message with event ID 1085
"Windows failed to apply the "Wpkg-GP" settings. "Wpkg-GP" settings might have its own log file. Please click on the "More information" link."

finally I get error 7034
"The "WPKG Control Service" service terminated unexpectedly. It has done this 1 time(s)."

In the Application-Event-Log I found Event Id 100 from source GPE with the message
CreatePipe returned an error.
Error code: 2
Error message: Das System kann die angegebene Datei nicht finden. (Translation The system can not found the file)"

Because of the stopped service, wpkg.js is not invoked after booting. Any hint so find the problem is therefore highly appreciated.