EDIT: I may have found the problem? It was because the mystcraft age was missing 2 region files.
I use Unleashed 1.1.3 pack with Gregtech, and in my survival world, i just created a mystcraft age.
It was all fine, until the end of the day.
Next morning, I opened up unleashed and i saw that my survival world was not there.
I checked Unleashed\minecraft\saves and i saw my survival world there.
I reopened Unleashed and it still didn't appear.
I copied the save file and reopened Unleashed again.
Still didn't work.
Any help or people who have the same problem?
I use Unleashed 1.1.3 pack with Gregtech, and in my survival world, i just created a mystcraft age.
It was all fine, until the end of the day.
Next morning, I opened up unleashed and i saw that my survival world was not there.
I checked Unleashed\minecraft\saves and i saw my survival world there.
I reopened Unleashed and it still didn't appear.
I copied the save file and reopened Unleashed again.
Still didn't work.
Any help or people who have the same problem?