KRunner hangs and is shown until the application is closed when it was used to start the applications with absent service is defined in X-DBUS-ServiceName item of its .desktop file (for reproduce scenario see bug #358315 for Skrooge-2.2.0 with such a typo in this field). When the application is closed, "KDEInit couldn't launch <path-to-app>" error message is shown and KRunner continues to run normally. Reproducible: Always
Also KRun::runService blocking waiting for the app to reply *** This bug has been marked as a duplicate of bug 361917 ***