Blueprint - Error While Saving Transition

Blueprint - Error While Saving Transition

It looks like a CRM update has just been done.  My blueprint has been working fine all day, but is suddenly coming up with an error message - Error While Saving Transition - every time a button is clicked even though no changes have been made to it.  If the screen is refreshed after button click, the transition has taken place... but not sure why the error is popping up.  Any ideas?