It's possible that you haven't assigned a texture to your material. If you don't assign a texture to the material, when imported into Lens Studio, the material that gets created assumes you want a texture and haven't assigned it yet. Thus, it gives you a pink and black checkerboard.
To fix your material:
- Find the material in the resources panel and select it.
- Check all texture properties on the material to ensure the texture is set or the texture property is disabled.