I changed the installer of the BETA3-0965b client exe for windows so all generated files from previous installations get 100% deleted.
There was a chance the new client shuted themself
down for safety reasons when it found outdated files.
The new installer will cover it.
When your BETA3-0965b client shutdown when
login to the server after you ugraded, redownload
the package here - it will then work.