This is why you should install it over top of an existing version.
What do people do that are installing it new for the first time? Should my 2016 not have given me every file needed? I have the Plus Pak as well. Seems like it should write every file to wherever I tell it to. There is no disclaimer that says "You must have last year's version to install this year's version." Very confusing.
Like you said, if I install it into c:\donkey, the installer should at the very minimum reach out into the hard drive and find old files and move them rather than setup pointers to c:\bb which may or may note exist.
I have a headache.