Was considering adding a chest outside Riverwood with a large quantity of every ingredient so I could mess around with Alchemy. Not to break the game or anything; I got some information on Dragonborn ingredients for a guy who does a Skyrim Alchemy Calculator, and wanted to check and see if the values of the potions I could make with those ingredients in-game would match what the site calculated. I therefore tried to load up the Skyrim, Dawnguard, Hearthfire, and Dragonborn ESM files so I could get the ingredients and put them into a chest. Unfortunately, the Creation Kit refused to load two Master Files, and aborted the load. This is odd, because I'm pretty sure that I managed to load up Skyrim.esm and Dragonborn.esm together when getting the information. What's going on, and how can I fix it?

This belongs to the Creation Kit sub-forum.

Editor.ini
bAllowMultipleMasters = 1

Or add the masters manually using TESVEdit

Add the following to the [General] section of SkyrimEditor.ini found in the same folder as TESV.exe:

bAllowMultipleMasterLoads=1