First, make sure your texture files have one of the following formats: BMP, PNG, JPG, GIF, TGA, or PSD. TriLib won’t accept any other texture format.
Make sure you have assigned the textures to the right material properties when exporting your model. Generally, standard materials created by commercial software like 3Ds Max or Maya are accepted. Any other material type may not be supported (except for PBR Materials).
Make sure your texture is embedded in your model (Formats like GLTF and FBX accepts embedded textures), or your texture is located in the same folder as the model.
If you’re loading your model from a ZIP file, make sure the textures are at the root folder of the ZIP file.
My model was loading on TriLib 1x but doesn’t load on TriLib 2
TriLib 1x is based on Assimp, an open-source project. Assimp works with more than 40 file formats, but some of them lack the needed stability and maintenance a professional project requires. TriLib 2.0 no longer uses Assimp, all file readers are written in plain C# and since it is developed by a single developer, a decision has been made in order to provide a more stable and complete product. TriLib 2.0 works with the industry-standard 3D file formats only: FBX, GLTF 2, OBJ, STL, PLY, and DAE (coming soon). Other formats will be included as well. So if your models use any format other than these, TriLib 2.0 would not work for you.