I just installed Dawnguard and the game works but when I try to load it in the CK I get this message and the CK crashes.

Assert

File: C:\_Skyrim\Code\TESV\TES Shared\misc\BGSLocalizedString.cpp

Line: 2871
LOCALIZATION: Error opening or reading strings file.
MASTERFILE: LOCALIZATION: Zero entries or empty block size read from strings file STRINGS/Dawnguard_ENGLISH.STRINGS. Strings will be missing.
Assert

File: C:\_Skyrim\Code\TESV\TES Shared\misc\BGSLocalizedString.cpp

Line: 2883
Failed to allocate entry array.
Assert

File: c:\_skyrim\code\tesv\bssystem\BSTSmartPointer.h

Line: 167
Null pointer

open up your SkyrimEditor.ini in the skyrim root folder, and you will have to add Dawnguard.esm to the resource list. Here's what it looks like with all the DLCs, just remove HearthFires & DragonBorn from these lines if you don't need them.

[Archive]

...
SResourceArchiveList2=Skyrim - Shaders.bsa, Update.bsa, Dawnguard.bsa , HearthFires.bsa, Dragonborn.bsa

Why are Dawnguard.bsa and Hearthfires.bsa added to the two first lists? I've added to three bsa to the last list, like you, and the ck loads them fine.

Hah, perhaps the first lists aren't necessary then. All I remember is I was frustrated when they weren't working and smashed together a mish-mash of internet advice until I got it to work finally . Has been working like this for several months now though, so can't be hurting anything.

Edit: Gave it a try and it does indeed work nicely with just the entries in the last list. Apologies for the sloppy advice, have edited the first post.

Oh, THANK YOU!

It's mad! Flipping Bethesda! Why doesn't the CK know that Dawnguard.esm is installed? It actually OFFERS it as a master to load, so why hasn't it updated it's own ini files automatically when I launched it?

I mean, it created the original ini files when I first installed it when I just had Vanilla "Classic" Base game Skyrim (or whatever the flip they call it!)

PAH!