**System Information**
Operating system: Winodows 10
Graphics card:
**Blender Version**
Broken: Blender2.81 alpha, 19-9-2019-13:32
**Short description of error**
Strange geometry solution with Mask extractor
{F7760461}
**Exact steps for others to reproduce the error**
With the file provided, original mesh and extracted mesh, select the bone and make a "Mask Extract" so you can see how it create a mesh with a bad topology mesh.
{F7760465}