The problem seems to be the launcher. It has the "Run as different user" in the "Advanced Options". Simply untick it and it will be error free. It doesn't prompt for password if you launch it this way, and it gives a message say it will run in read only mode.
In the launcher "Command" field, simply add kdesu at the beginning and it will run fine. -- "Could not find mime type" https://launchpad.net/malone/bugs/32139 -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs