Just retried by downgrading and running autoupdate and it worked. Can you please retry. Did the installation work without problems and only afterwards the server did not run?
In that case please try starting it manually to see where it fails in your case.
Start manually:
execute cmd.exe as administrator then run:
"C:\Program Files (x86)\Repetier-Server\bin\RepetierServer.exe" /c "C:\Program Files (x86)\Repetier-Server\bin\RepetierServer.xml"