Chuske

I'm having some issues using UABE to replace images files in the game "Buzz Aldrin's Space Program Manager". I can extract the images ok but they won't work if I export images back into the asset and use them in the game. In fact even if I just uncompress the asset with UABE, and do not change or replace the texture the image appears corrupted in game. The game was created with Unity 4, when you needed a pro license to build the asset bundles and Unity 5 onwards asset bundles are not compatible with the game. Any ideas as to why even just uncompressing the original asset bundles makes the images appear corrupted and is there anything I can do? Thanks.