LW 8.4.1 Install: Removes Thread Manager

I have a Power Macintosh computer and I just installed LaserWriter 8.4.1 and now I cannot play MPEG movies. What should I do?
LaserWriter 8.4.1 checks for, and removes, the Thread Manager. It does not check to see what version of the Thread Manager is currently installed. Thread Manager 2.1.5 is required for the QuickTime MPEG Extension to work properly.

To be able to view MPEG movies again, reinstall the QuickTime MPEG Extension and this will reinstall the correct version of Thread Manager 2.1.5.
Published Date: Feb 18, 2012