Users can't log in and user avatars disappear after moving WP website to a VPS

Hi,

I have had to move a WP website to another server, and I chose a VPS. Since doing this users haven’t been able to log in and user avatars don’t show up on the site.

I am thinking that this may be a permissions issue, but I’m not sure. I would be glad of any help because I have some frustrated users right now!

Thanks,

Nick