Problem:
KDE tries to start after login. Machine freezes completely. Sometimes it takes a little while...

Workaround:
1. Do not login
2. Press "Ctrl+Alt+F1" --> switch to tty1
3. Login with your username and password
4. Type "sudo apt-get install nvidia-361" --> installs the nvidia-driver

----> for other types of graphics cards try "apt-cache show nvidia- <TAB> <TAB>" --> lists all avalable drivers, choose one to get information, replace the right package in the command above

5. Type "sudo init 6" --> reboots

Happy to be back on Neon again! Nice work!