Gmod seriously fucked

‘RealFrameTime’ (a nil value)
ERROR: GAMEMODE:‘HUDPaint’ Failed: gamemodes\sandbox\gamemode\cl_notice.lua:91: attempt to call global ‘RealFrameTime’ (a nil value)
ERROR: GAMEMODE:‘HUDPaint’ Failed: gamemodes\sandbox\gamemode

That spams when I join any game. Also, when I click on extensions or achievements in the main menu, nothing happens. Hell, there isn’t even a fucking q menu. Wtf happened? It was all working fine until I installed addonisimo, which i deleted, but this still happens?

Last time I got this issue it was only resolved after I reinstalled Steam. You could wait until the next update to see if it fixes it, though.