Trying to upload new avatar image. Fails to replace image if file with extension already exists.

IE: filename.jpg uploaded as

but a different filename.png (or gif) upload fails repeatedly to change the file at (gif)

trying to upload filename.jpeg failed entirely.

While I'm on the topic, why do animated gifs, even when within specifications, upload correctly but fail to run and why do they not show the starting gif in the animation sequence as their defaults?

The so called "help" is no help at all on this.