Blank workspace

Hello everyone.

I have a problem with my workspace. I was working on a project, everything was fine, I saved it and when I re-opened it, the workspace was blank. The layers are there, visible not in the workspace. I also used timeline to create a project ( but I don't think this is the issue ). 

If you have a solution about it please do tell because I have tried everything but I couldn't solve it. 

Thank you.