Heaven-forbid you want to upgrade a package that exists in all 130 projects in the solution (not my call to have that many projects) - you may as well take a long lunch. I will try to make that the last task of the day so I can let it run for as long as it needs to.
The VS UI for NuGet is terribly buggy.
Try to build a C++ or Android project and then go for lunch instead.
NuGET is great.
Most likely someone modified the packages for an individual project and not the solution as a whole. Always manage packages at the solution level and your much less likely to have these issues, unless you have multiple solutions...
Basically, it 'just works' for simple senarios, its just not very good for anything else.
If you want a comprehensive guide to why its not awesome look at the 'packet' website, they cover the issues quite clearly.
^ you can actually use local dependencies, but its irritating and poorly supported (still uses the global system cache, forcing a cache flush to update).