Security Update blocks Classic: the solution

A reader sent us Apple's apparent official reply on the subject of Classic not launching after updating Mac OS X 10.1 in some cases (see previous coverage):

"Apple is aware of potential issue involving a recent Mac OS X update which may prevent the Classic environment from opening. If you use Mac OS X and were affected by this issue after downloading a recent Mac OS X update, you may resolve this by downloading and installing the Security Update10-19-01 (version 5L14) from here."

This concurs with reports we have now received from several readers (including Steve Organ and Tom Foerster), stating that the problem occurs only when using the Software Update System Preference to install the Security Update. If you use the downloaded stand-alone package file, the problem is avoided. Reinstalling via the stand-alone package, even if you have already installed the Security Update via Software Update, eliminates the symptom.