I mirrored my Duck – after I applied the scale and rotation, of course-- with an empty for faster UV fixing. However, I discovered this:
After checking it out a bit more, I found out that there were some doubles. So I selected all and merged them, but there were still more. I tried changing the merge distance by putting in zeros, but no matter how many I put in, nothing happened. This is turning out to be super weird for me so, W.D.I.D.?