Well we discovered that Mystcraft has an internal age limit. Unfortunately this is not only hard coded into the clients but as well as the server. We have found a way to not only reuse Ages that were wasted when attempting to create ages for previous donors we also created a way to import ages you create in single player without instabilities!
So what does this mean? Well we can no longer afford risking creating new ages on the server. so going forward we will be on a supply your own age from single player basis.
When you donate for a private Mystcraft age you will need to go to single player creative and create your perfect age that you desire. You will then submit your Age files (very small) to us here on the forums and we will import the age.
Remember the number of ages left is LIMITED so once they are gone..... they are gone.