Purple and Black.. refection error

Ok i know that purple and black mean missing textures but sometimes when I’m playing, all the the reflections will turn purple and black. just the reflections over the textures. it happens sometimes when creating spawn icons. what causes it and is there a console command to correct this with out having me restart my game.

that happened to me on the roleplay server

This is a problem with the cubemap. It occurs when you alt-tab out of a game. Only restarting the game fixes it. (as far as I know)

Happens to me often, simply Alt+tab out, and then return to the game.

When i alt tab, and open the window again, I can hear all sounds and walk around, but it just keeps displaying my desktop.

There is a command, but it might crash your game. You wont be able to see shit for about 2 minutes.
Just put buildcubemaps in console, and the game will rebuild all the cubemaps in the current map. Will take long for big maps.