Xcode hanged after upgrading to Xcode 6.3

After updated to 6.3. When I restart Xcode, it auto reloading my working project. But it stuck with "Loading..." message.

When I try to remove userdata in the project:


Not working. Then I try to remove autosave information:

~/Library/Autosave Information

Still not working. Lastly, I try to remove the the Xcode save state

~/Library/Saved\ Application\ State/com.apple.dt.Xcode.savedState

Then Xcode will reset to default without loading previous project. After I open the project manually, everything back to normal.