Your message is telling you that ScoreboardPkg_slv is not compiled into the OSVVM library. You should be able to bring up ModelSim and look at the library and see if you agree.
Then also look and see if it is in your working library (sometimes named work, but it is the library into which you are compiling). Maybe it puts package instances of ScoreboardGenericPkg in your working library instead. If you find it in your working library, simply change the library reference to work.
