MOSS: Unknown error on Central Admin

Problem:
The front page of the Central Admin site works, but clicking on any link on the page gives "Unknown Error" (just black text on white background).

Workaround:
Reinstall MOSS and hope that it won't break again. Don't waste your time fiddling with Configuration Wizard, it won't do any good.

Ok, you might find the cause of the error by disabling custom error messages on the site.

Solution:
Many, depending on the error.