Yasuhiko, The crash seems to occur after you have built a project, closed kdevelop and then reopened kdevelop and then choose open project to open another existing project. Simple test case. Just create the two examples kde simple application, and kde simple application with designer. Build them, then try and open the other project, with Project -> Open Existing.. and with a couple of the sources open try and modify a source. When the bug occurs, most of the icons in the statusbar (valgrind, debug, etc..) disappear and often when you open kdevelop with an existing project nothing is shown in the textview part of the window. You see the file-list, but the textview is blank and no tabs from last time are shown. Really odd. I've not had this issue in 15.4. I'm not sure what else to check, but in addition to the stderr messages shown in the original e-mail, it also looks like something in the project is corrupted as a result. That may explain the textview problems. -- David C. Rankin, J.D.,P.E.