Editors' Note: Check MacFixIt for OS 9.1 Troubleshooting, What's New, Tips & Tricks
The Mac OS X Public Beta and Mac OS 9.1 are not compatible. If you install Mac OS 9.1, the Classic environment in the Mac OS X Public Beta will no longer function.
If you use a Language Kit, the full install CD is required to upgrade your language kit at the same time as you are upgrading to Mac OS 9.1.
The following Macs must order the update CD to install 9.1: PowerMac series :6100, 7100, 8100, 8115 and WorkGroup Servers 6150, 8150, 9150.