Topic on Talk:UPK Explorer
so yes I saved one file and made sure it stayed in the same folder (export PF_DXT1), converted it to png (deleted old .dds), upscaled .png, converted upscaled .png to .dds (deleted upscaled png), then moved upscaled .dds to the correct folder (Export PF_DXT1 to Import PF_DXT1).
The program did not find the file so my guess is converting it to png made it lose its formatting.