After installing Apple Displays 1.6, I can no longer use
AppleTalk or TCP/IP, or anything related to networking (Chooser,
File Sharing, etc...).
SOLUTION:
Some people are reporting this, and I don't know why exactly this
happens. It seems to only happen on NuBus-based computers,
including the PowerBook 1400, 5300, and Duo 2300c.
To get OpenTransport to function on these machines (with Apple
Displays 1.6), temporarily disable the Display Enabler extension
using the Extensions Manager, restart, activate AppleTalk and
TCP/IP, then re-enable the Display Enabler and restart again.
A better solution would be to install OpenTransport first,
activate it and then install Apple Displays 1.6.
