[Soala]

First, what are you trying to do?

If you are trying to use the tileset on your server, best is to upload it in the images folder of your file browser. It needs to be uploaded on your server to work.
Secondly, do not name it pics1.png but rather another name, for example servername_tileset.png. This way, people visiting your server will not have their tileset used on other servers replaced by yours.

If you are trying to load this tileset in the offline editor, then I suggest you tell us how you did exactly to try to make it work.