Weight painting translation from Blender 2.8

I am trying to upload a model - wolf - 3D model by jpholmes122 (@jpholmes122) [1217262] - Sketchfab

One of my animations (run animation) has some vertices where they shouldnt be


In Blender I do not see this, it looks fine.

What could be the problem here?

Sketchfab calculates weightpaint a little different than blender does it, check out older thread someone made here:

Blender has a higher tolerance of how many bones can affect the mesh without breaking it.
But this does not mean that those weight errors are not there, you should check if that vertex is influenced by another bone that should not have an effect on it or add a little more weight to it, maybe try exporting to fbx, since this gives usually a slightly better result.Perhaps you have overlapping Vertices?

Or, if none of this helps, you may have to ask one of the staffmembers hosting sketchfab to do the reprocessing for you.

Sadly I cant do that for you.