vshost causing sta thread exception error again??

Similar to this thread, but up to date:

https://social.msdn.microsoft.com/Forums/windows/en-us/dee32dbf-be81-46d5-84f6-72fc0f22e960/dgvcomboboxcolumn-gives-threadstateexception

c# app with datagridview with combo box cell that had been working ok in vs-2013 suddenly started throwing sta thread state exception while running in debugger.  using 'start without debugger' and it works ok... or turning off vshost process in project debugger properties and it works also.  is there something recently that could trigger this???