Xcode storyboard: Internal error. Please file a bug

While editing in the storyboard, specifically assigning a view controller to a specific class, I suddenly encountered this error when I wanted to run the project.

Main.storyboard: Internal error. Please file a bug at bugreport.apple.com and attach "/var/folders/79/_jh611t15qsfcx165_jv_20h0000gn/T/IB-agent-diagnostics_2015-10-28_00-33-12_730000".

And now I can't run my project anymore. I couldn't find any information regarding to this anywhere else. Did anyone encounter this before?

Solution 1:

I faced the same issue. And it was solved by cleaning up the build files.

cmd + shift + k

AND

cmd + option + shift + k

Hope this helps Thanks.

Solution 2:

The following steps will stop your problem.

1. cmd + shift + k
2. cmd + option + shift + k
3. Restart Xcode
4. Restart Mac.