Hello

let me try and understand...I have Kxstudio installed with KDE SC 4.12.3

"find..." worked perfectly fine, and then lately it announces "invalid protocole" in a red box, as soon as I type any letter. Yesterday I did a sudo apt get update and on reboot it worked again, but just for a while, as suddenly, without any other change, it went back to the "invalid protocole".

Kfile works fine, I havelibbaloocore4 files4 widgets4 ans xapian4 installed

what's wrong?

Which search options are you trying to use? Find by content or by filename?
Also, does it mention which protocol is invalid?

Maybe related to https://bugs.kde.org/show_bug.cgi?id=339866 ? According to the reporter, installing "baloo", "baloo4" and "baloo-utils" fixes the problem.