Turns out the error was generated because ..tf\materials\vgui\* was on the list of excludes on the pure_server_whitelist.txt on the server I was connecting to.
Mine simply disappeared with the replay update. I decided it would be wise not to reinstall it before it was fixed to work with the new standard menu buttons. I was going to wait until the contest ended before I mentioned it here.
Oh OK, that's handy to know. I'll fix it up later today then. Last time valve updated the main menu this was causing crashes so I assumed the same thing would be happening. Glad to hear it's not.
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