Maya rigging tools problem. I can't back to skeleton placement stage

Hi. I can’t back to skeleton placement stage, when i push button standart message pops up:

“Depending on the magnitude of your edits, you may lose skin weighting information. The tool saves out skin weight information and tries to restore if for you after your edits are completed.”

But then nothin happens. At previous launch of maya there were no such problems. I’ve tried check this on another rig i made a while back and it works fine, but not for some other recent rigs. How can i try fix it?

The problem seems solved. There were duplicates in the meshes names.