Hello,
I'm using the "Mix and Match" skin system with Sprites as source images and everything is working great in the editor. However, when I build to Android or Windows, many of the attachments on my skeleton appear as white polygons, like this:
Here's the strange thing though: When I create a new project and only import the Spine runtime (3.7 or 3.8 ) and build the Mix and Match Equip example scene, everything works fine. But then I imported that example scene and its into my actual project to test them out there. Things work fine in the editor, but the same problem exists when built: 
This is from a Windows build. Things work fine until the "Done" button is clicked (and the Skeleton's skin is set to the result of a call to Skin::GetRepackedSkin), then the white polys appear.
Initially I thought my issue must have something to do with my code regarding the attachment generation and replacement, but now that the problem is shown to exist on the unmodified example scene, but only when built from my project, I realize it must be something project-specific.
My question is, what about a project could cause this example scene to display improperly only in built executables? My Graphics and Player Project Settings are identical to the working example project, and I am otherwise stumped. I suspect this could have something to do with PMA textures but I tried re-exporting my skeleton without PMA and using a different shader and still saw the same issue.
I'm hoping someone might have a vague idea or suggestion of where to look next. I'm using Unity 2019.4.10f1 and Spine runtime 3.8, and as I said the example and its code is unmodified.
Thank you,
-Sean
EDIT:
I have it solved, for now. I'm still not sure what the exact problem was, but I ultimately created a new Unity project, then copied its generated files from the ProjectSettings directory over my project's existing ProjectSettings files. Now everything displays properly in the build.
I thought maybe it had something to do with me using the Legacy Sprite packer, but changing back to Legacy doesn't reproduce the issue, so I'm truly stumped. Nuking all the ProjectSettings files seems to have worked and even though that is a headache itself, I'm happy to be able to move forward even though it would be nice to know exactly what the issue was.
