visual studio 2015 c++ editor broken, solution? -

after install in vs2015 (intel mkl library vs integration) c/c++ editor fails show except tab on top. no window, no text, nothing. dug bit deeper: .txt file displays fine, .cs well. when set in options filetype .txt needs editing in c/c++ editor, .txt stopped displaying too. have compared every option in tools->options, including environment options, normal working rig, found nothing. resetting default options did not help, nor did changing color scheme. removed intel directory common7/ide/extensions, no improvement. not know more secrets kept, tried registry search, found no clues. appears match, dll language specialization in vxpackages. anyone, before try repair installation? in advance, jan

edit: got editor on track disabling productivity power tools 2015. took me half day. connection intel install doubtful!