First time I have come across this here, but a quic google of the error has shed some light, an may give a possible solution.
Ok so as i understood it, i had to install the launcher of BSG on the same Hard Drive (wich didn't cause any problems before idk why), i tried and it worked for the moment but i stay very carefull about that because with this bug it already happenned that i could launch the games a few times and then it doesn't work anymore. Hopêfully this isn't the case here... thank you very much for your help and if this happen again i will tell you.
Have a good day/evening !