These are issues known by the authors before release and reffered to on the Rom Browser. This information is provided so that you don't wonder how to fix/adjust them or not if some of these things are not fixable.

Definition of a "Known Issue", "Core Issue", "Video Issue", Audio Issue", Input Issue", Ect.

You will see this used a lot on the browser, unfortunately. It simply means:

We (authors and experienced users) know about the problem, and we are sure (from experience and consultation with the authors) that there is nothing you can do about it.

Issues listed under "core" are problems within the .exe, and cannot be fixed except by using a different emulator with a different core (do not ask the Project64 team which emulator to use, we do not know!). Issues listed under "plugin" (or "[video]") etc. are problems within a plugin and could in theory be solved by using a different plugin (do not ask the Project64 team which plugin to use, we do not know!).

If a solution to an issue is found (a big "if" - it is not likely), the answer will be added to the browser or the Project64 GameFAQ, if something is mark as a known issue, and you still ask how to fix the problem, you are going to annoy people. Please don't do it.