Hello everyone.
This is my first skin but there is a problem here. I don't know how to fix it.

Just add some extra blue pixels around that area on hud, top and right side. It should fill it in. You probably have some edge cutting after resizing the skin back to 1024×1024px. Here we could really be talking about a single black pixel somewhere. Where is it exactly you have to find out.

Quote from rane_nbg :

Just add some extra blue pixels around that area on hud, top and right side. It...

You were right. I found the problem. Thx for the answer.