I have been away for a while, so when I tried to open up the Dawnguard master file in the Creation Kit to create my own Serana, it crashes to the desktop--right after I select "Yes to All.?!?" Yes, I did check "DawnGuard" and made it active too. What has changed?

I have also added the "bAllowMasterLoads=1" to the SkyrimEditor.ini file, as well. Does anyone have an idea what the problem is? What have I done wrong? Thank you.

Add bAllowMultipleMasterLoads=1 under [General] in SkyrimEditor.ini