load file and get problem when load pak

I use unrealpak.exe pak assets files,then I use C++ code load the pak and load the umap from pak,but get the problem here, could any body help me ? I 'm sad.

I see the log,and find “LogLinker:Warning: The file ‘…/…/…/HousePhoneProject/Content/WebCache/mobile/resthree/Room1/HDR/hdr-075.uasset’ contains unrecognizable data, check that it is of the expected type.” .
the log of All loaded assets are those warnings. what should i do. Do I use unrealpak.exe wrong ? I think this is the bug in engin.

the texture of the mesh is wrong !!!