I have changed how I handle the identifiers of the Mystcraft ages. Basically I’ve loosened the binding of the dimension ids and the age ids, so age ids are no longer necessarily the same as that of the dimension. The reasons for this will come later

This means that the names for the ages’ data folders has changed formats. For the next release it will automatically rename them to the new format, so I won’t break saves. On some following release that will stop happening, though, so be sure to ‘upgrade’ all of your ages in advance. ;)

It won’t be a serious issue either way. It’s a simple matter to change the folder name manually. I just didn’t want to force people to do that for all of the hundreds of ages they have created. ;)