"Failed to read 3840522 bytes" HELP PLS

[FrostBite2.0]

Hello. When I came into game I pressed a joystick icon in the right bottom corner and put a tick on l4d after that at me game took off and at its start there is an error of "Failed to read 3840522 bytes". Help please

[c👌de_g🎷]

Try starting up and verifying L4D, and verify Garry's Mod.