Comment 1 for bug 575968

There were no changes to mupen64plus. Please contact the sdl maintainer or your the maintainer of the graphics driver.

You didn't provide any kind of information about your used plugins or your graphics driver. That would be useful in that kind of bug report. rice just uses SDL_WM_ToggleFullScreen to enable the fullscreen mode and glide64 just sets the SDL_FULLSCREEN flag. So it should not be a real mupen64plus problem if it worked before.

It could also be kms or uxa related if there were such changes in your driver. Have you tried to use a resolution which is exact the native resolution?