Texture file has black background

When I exported this mesh 9 months ago, its texture file filled in all the spaces with blurred colors. Now, when I export the same model, the spaces are filled in with black. This is a problem because when I bring the mesh and UV into Unity, there are black seams all around the model. Is there a setting that will export a texture with blurred colors?

The model:

 

The old UV with blurred gaps:

The new UV with black gaps (bad!)

 

The mesh and UV in Unity, where seams are visible:

it is a bug!

link workaround:

 

https://support.capturingreality.com/hc/en-us/community/posts/360032373692-Bug-17234-Exporting-UVs-no-longer-have-blending-producing-unusable-UVs-for-editing