and some time i cant open it until i reboot my computer.
Sketchup wont open , just start then with out any bugsplash just close itself.
I had this issue once - I found the folder where the temp files are stored (away from my computer now) - on a Mac I believe it is in Library>Application Support>SketchUp and then one of the subfolders. I cleared out a bunch of recovered files and I suspect one was corrupted and SKP was trying to open it at launch.