Production Calendar - Vantage 3.0

I am struggling with an issue in using the Production calendar. I can not
save any changes I make to it. I will add in a holiday, or a Saturday, and
I come back, and none of my changes are saved. I recently broke up most of
our machines into their own work centers, to make scheduling easier and the
loads more accurate. Could that have caused a problem? Changes will not
save in either a custom or the plant calendar. Please help.

Jim Selinger
Production Scheduler
Bley Engineering
Elk Grove, IL