[v8i SS10] Unable to open DWG2007 after upgrade to SS10

DWG 2007 no longer opens after upgrade to Microstation SS10 (08.11.09.919) shows "bad file" error or contact administrator. Creating new empty file with delivered DWG 2007 there are no issues. There was RealDWG 2014 left after upgrade uninstalling it doesn't help. SS10 installed RealDWG 2016 (08.11.09.919).