April 2008: Quicken suddenly stops working
Nobody seems to know why, but Microsoft suddenly released the .Net 2.0 Service Pack 1 on a Thursday, one week before tax time, via the automatic update chute. The patch itself had been available as an optional, manual download for months, but somebody flipped the auto update switch.
Within minutes, Quicken users were complaining. QuickBooks got hit, as did TurboTax and software from Commerce Clearing House.
How bad was it? If you were bit, uninstalling, then reinstalling Quick Books didn't solve the problem. You had to uninstall, then reinstall .Net 2.0 -- if you could get it to uninstall.