Almost I find out what make this issue
As this is new iMac I reinstalled 3rd party callouts which usually works before with no problem
I found that its happen with one of them projects if the final cut open it and stuck the time line
I have duplicated the same project and removed the call outs from the project , and it works fine now.
but anyway its seems not really stable the FCPX because time to time it when I open it I can't find the projects and it works like its first time run final cut , and it give me the welcome screen.