Im able to open the fallout 3 master and one DLC master but no more than that, is there some trick to opening up all of them together? kind of annoying since i want to use items from a couple different DLC's.
Yep what you need to do is open GeckCustom.ini and find this line: bAllowMultipleMasterLoads=0. Change the 0 to 1, save and it'll let you load multiple masters.