Xcode 12.3- No Graphics, Internal Error in IB???

Hi,

Last night, when I was working on autolayout constraints on main.storyboard all UI elements became invisible, I cannot see photos and button looks on main.storyboard file. But it on Simulator it works properly. And also it say "An internal error occurred.Editing functionalty may be limited." How can I fix this Xcode bug?

Note: I already tried clean builder and removing DerivedData file. It did not work.

thanks