Re: Buddypress – overall site – home page
mu-plugins is the correct location.
The information you have provided in your posts don’t have enough information in them to tell what is wrong. That’s why we have asked various questions.
The short version would be that most likely you have not followed the install directions correctly. For example, the expected callback error means that a function call is being made to a function that hasn’t been defined. 99.9% of the time with a plugin that means one or more files are in the wrong place.