If this is the first time you're installing MB, you won't be able to give us the version number by Help > About since you can't launch the program.
Is this the Store version? The full installer? Or Portable? If either of the last two, try installing into a non UAC Windows folder. For example, C:\MusicBee. Or even better, on a partition other than C.
C:programfiles(86)\musicbee\bacs.dll
I'm assuming you typed this in and did not do a copy/paste, correct? As far as I can recall, there is no "bacs.dll" file contained within the MB installation.