Mac OS X: Classic System Folder Does Not Work With Earlier Versions of Mac OS X After 10.2 Update

After a Mac OS 9 System Folder has been updated with Classic system resources from Mac OS X 10.2, it should not be used with Mac OS X 10.0 through 10.1.5.
Symptom

Classic is not usable after it is started, and an alert box you cannot dismiss may appear with this message:


Note: The System Folder is not affected when used independently of Mac OS X.

Solution

Do not use a Mac OS 9 System Folder with Mac OS X 10.1.5 or earlier after it has been updated by Mac OS X 10.2.

You may use the following temporary workaround to use this System Folder within a Mac OS X 10.0 through 10.1.5 Classic environment:

Notes
Published Date: Oct 10, 2016