TF2C Crash during first load screen, no crash message or error report.

[Aerotactics]

Every time I try loading the TF2 Classic client, I see the valve intro, then a screen with a map in the background and loading text in the bottom right, then the game just closes.

I am already in the beta_test branch on Source SDK.
I already see the game in my Steam list.

Final test is verifying cache.