OK I have searched on the forums and only see mention that you are unable to Diplo Annex other countries while you have a Regency Council in posession of your throne, however can anyone tell me if it is possible to Diplo-Annex a vassal that currently has a Regency Council on the throne? I have been trying to Annex Mecklenburg for several years now (started with a king then they died and is now Regency). If it is not possible I will just get max rep and stop trying.