Does anyone know why jpegs can no longer be uploaded as avatars?

i cannot understand what has happened just now??? every time I try to change avatars, no matter which one I select from jpegs I have used in the past, the new avatar fails to upload, I keep getting back the messages: "photo failed to upload" at the top and "Sorry, this file type is unsupported" at the bottom, even though I'm using all the same avatars that I was using before???
this happens with both smaller personal avatars and the larger profile banner avatars?
does anyone happen to know what is causing this???

thanks

@brrr said
i cannot understand what has happened just now??? every time I try to change avatars, no matter which one I select from jpegs I have used in the past, the new avatar fails to upload, I keep getting back the messages: "photo failed to upload" at the top and "Sorry, this file type is unsupported" at the bottom, even though I'm using all the same avatars that I was using before??? ...[text shortened]... and the larger profile banner avatars?
does anyone happen to know what is causing this???

thanks

@brrr said
i cannot understand what has happened just now??? every time I try to change avatars, no matter which one I select from jpegs I have used in the past, the new avatar fails to upload, I keep getting back the messages: "photo failed to upload" at the top and "Sorry, this file type is unsupported" at the bottom, even though I'm using all the same avatars that I was using before??? ...[text shortened]... and the larger profile banner avatars?
does anyone happen to know what is causing this???

thanks

@Very-Rusty
Do 'Gifs' still work Rusty?