Suddenly, after I closed Xcode with two projects opened, it stopped to launch. When I started Xcode it was trying to load projects and failed with error. I couldn’t open any project.

After some search and some experiments I finally found a solution to this problem, that might look not very simple and lying on the surface. That is why I decided to post about it. May be this solution is not very good in case you don’t want to loose your unsaved code, but it works:

Go to your libraries folder and delete the contents of Autosave Information folder.

Here is how to do it:

1. Open Finder

2. Shift + Cmd  + G

3.~/Library/Autosave Information, delete it

4. It is also important to clean your trash bin!

Then try to launch Xcode.