@carter883 : Reportedly, data packaged by UE4 can, and are here, cooked. That means data necessary for the editor to open and process these files but not for the executables to use them are stripped from the packed files. So it seems we can't use them as is with UE. Maybe the Ueviewer can extract and reinject graphic assets into the pak (idk), but I don't think you can unpack, edit and repack with the current bms script. Now,the editor has a c++ api with a library dedicated to the handling of pak files, so maybe part of the solution lies there.