Hi, I was playing around with KDE the recent day. Everything is going pretty well until I call up Terminal in File Manager. It was first opening the Terminal but not Konsole. I tried to change the default Terminal but it doesn't work. And then I have no idea when it was broken and now it's stuck.

System settings -> Personalisation -> Applications -> Default applications -> Terminal Emulator, set it to whatever you prefer.

FWIW: see the red text in my signature...