my 2018 sketchup is been crashed when ido my projects
Do you get a BugSplat report? If so, Trimble probably wouldn’t be very interested in it considering how long SketchUp Pro 2018 has been out of support, but you could post the first few dozen lines here.
What operation was being performed when SketchUp crashed? Is the crash repeatable? Does it occur on all SKP model files, or only one model in particular? If it is on all models, perhaps there is an extension that is to blame?
If it is only one model, you could post it in a new reply (or upload it to a file-sharing site and post a link if the file is larger than 15MB or so), and a clever user here might be able to spot something fishy about the model’s contents.
I don’t see any bugsplats from you. If you get one, send it in, then I can try to tell what caused the crash.