Would Like Assistance ^^
 

If you are using a picture off the internet like some picture hosting site.

Drag the photo to make it in a new tab where it is the only thing on the page, copy the address bar.

Click the insert image option on the text box, paste and save signature.

If a new picture takes the place of the one designated to the address, your picture will also change, but if it doesn't you don't need to worry about it.

You can't save a picture directly to AF anymore as far as I am aware.

Bugs like that happen when the site gets sold to a new person who doesn't seem to remember he bought it.