Noticed this :
https://www.reddit.com/r/Games/comments/4xiyid/_/d6g96lx
<blockquote class='quote\\_blockquote'><dl><dt>Quote:</dt><dd> </dd></dl><div>
You can easily bypass the nagware on PC:
15:49 <@xxx> You just edit the config file
15:49 <@xxx> of Project64
15:49 <@xxx> [Support Project64]
15:49 <@xxx> Run Count=-1
Wouldn't be surprised if it's patched at some point in the future.
[/quote]
with people reporting it works for them.
Can't say as i'm still using Project64 2.1 that does not have that. But i have read report that 2.3 isn't very good in performance.
For the crashes , i had a few with the Legends mod, be sure to check the thread some solution are around in it.
Notice that if you want to use Project64 2.1 be warned that the installer for it has adwares , so either be very cautious to what the options are, or install it through a sandbox and move the installed directory out of it so the crap does not touch your computer, or get a version without the adware/toolbar available around, like here :
http://www.1emulation.com/forums/files/file/1-project-64/
Apparently 2.3 does not have the adwares in the installer anymore, only the annoying nag screen.