System Information
Operating system: Windows 7
Graphics card: Geforce GTX 1060
Blender Version
Broken: 2.80, hash: 96f762500ef9, 2019-01-07
Short description of error
Vertices that are very, very close to each other that they are on top of one another can't be welded together using weld/remove doubles UV in the weld/align menu.
Exact steps for others to reproduce the error
- Make a simple UV map for a simple shape like a box, and go to the UV map editor window to edit your UV map.
- Split one vertex into two vertices so they are right ontop of each other.
- Select both using any selection tool that works for you.
- Open up the weld/align menu.
- Choose weld or remove doubles UV to try and merge them together.
- Deselect and select the "vertex" again and then move it around to see it still being split.
One workaround I found to this problem is to slightly move one vertex away from the other vertex, then select both and weld them again. Then it works.