What I did was put the dawnguard.bsa on the "SArchiveList=" section also and it worked for me. In fact, you guys inadvertently helped me with this problem. [Archive] bAllowMultipleMasterFiles=1 bInvalidateOlderFiles=1 SArchiveList=Skyrim - Textures.bsa, Skyrim - Meshes.bsa, Skyrim - Animations.bsa, Skyrim - Voices.bsa, Skyrim - Interface.bsa, Skyrim - Misc.bsa, Skyrim - Sounds.bsa, Skyrim - VoicesExtra.bsa, Skyrim - Shaders.bsa, Update.bsa, Dawnguard.bsa SInvalidationFile=ArchiveInvalidation.txt iRetainFilenameOffsetTable=1 iRetainFilenameStringTable=1 iRetainDirectoryStringTable=1 bCheckRuntimeCollisions=0 bUseArchives=1 SResourceArchiveList=Skyrim - Textures.bsa, Skyrim - Meshes.bsa, Skyrim - Animations.bsa, Skyrim - Voices.bsa, Skyrim - Interface.bsa, Skyrim - Misc.bsa, Skyrim - Sounds.bsa, Skyrim - VoicesExtra.bsa SResourceArchiveList2=Skyrim - Shaders.bsa, Update.bsa, Dawnguard.bsa