iMessage Fails to Send or Receive Photos For the past 4-5 days, I've been unable to send or receive photos with iMessage.

If I send, it hangs for a couple of minutes and then returns a "failed to send" message.

When receiving, little "tap to download" boxes come through, but the download progress never moves beyond 0kb.

The messages are definitely going over iMessage and not MMS, as I have cellular data turned off to prevent international roaming charges, and I send from my iCloud email.

The usage page was showing 2GB of free space, so that shouldn't be an issue. Since the problem started, I've tried both following the instructions here as well as doing a factory reset and restoring from a backup. The problem still persists.

Does anyone have a similar experience or an idea as to how this can be fixed?
I had this same issue a few months ago and I resolved it by turning off iMessage in Settings - Messages and then turning it back on.