Hmm – what operating system are you on @martinshin?
I have a feeling that it could have been the version of Blender it was saved with (beta) and the official version having issues on certain operating systems. (I’m going to guess you’re on a Mac like me – which has about 4 times as many bugs as Linux/Windows)
You can try downloading the rig again or relinking the character to a fresh file rather than course source file while I dig into it.
(I’ll try to get to the bottom of it)
