Kde plasma 5.27.10 freezes

Hi, I recently installed kde plasma desktop in my ubuntu 22.04lts and it worked fine until I added a application from discovery (firewall app.) but there were too complicated install instructions, comparing to gufw, so I removed the firewall application. After that the whole computer freezes nothing worked, I had to shut down from computer. I started again computer and when the kde logo appears with user and password I write my password and enter then the computer freezes again. I tried many times and allways the same happens after kde logo password and enter. Luckily I had old 20.04 ubuntu live dvd, and installed ubuntu 20.04lts and after that I upgraded with terminal to ubuntu 22.04lts again. Sorry of my bad english. I did like kde plasma desktop, but  I'm not sure if I would try it agai
 n. Have a nice spring time. From Hans W.