Model Troubles

I created the model using the mod Tabula. I properly parented the pieces together by connecting them. I exported the texture map and edited it using the program called GIMP. I laid out the textures into the model, then exported the model. In MCreator 1.7.9, I created the mob element and named it accordingly as a Trilobite. I imported the texture, and put in my model. I did everything else as per normal. When I was finished, the element was said to be problematic, so I removed it. I recreated it, and it came up with the same results. I want to find a way to create this custom mob without all of the hassle of having to keep redoing the mob.