After reinstalling my PC, including VS, my code compiles, but certain nuget packages' using statements (and thus, lines using the package too) are underlined with a red error as if the package was not referenced. However, the code compiles just fine. While this could be just an annoyance, pausing the code and modifying even just a space in a comment now does not let me continue like it used to.
I'm sure I'm just missing some cache clear somewhere, but so far I have not found a solution. VS clean/rebuild, clean and re-open VS, bin/obj folder deleting did not help, restoring nuget packages says there is nothing to restore.