I’ll look at it in a little bit, I have a feeling I know why it would have lost the texture images but just in case which model(s) specifically was it?
Viewing post in 3D Model Converter for GameMaker comments
So tested it on another computer and the issue still presisted. However loading in a model from kenney's Retro Medieval Kit worked fine, the texutres loading in without issue. Can Penguin just not load colour from mtl files?