tagavari
commented
3 years ago .heic is a newer image format primarily used by Apple devices, and it unfortunately doesn't have very good support outside of the Apple ecosystem. iMessage devices will fall back to regular formats like .jpeg, but will use .heic if both devices support the format.
AirMessage does not support .heic on-the-fly conversion, but this certainly sounds like something that should be a feature. This is also an issue with the web client, so I'll see if I can make it in to a future update.
I am having intermittent issues receiving attachments. When they download they sometimes display normally but occasionally they display as filename.extension (majority a .heic). When i tap them, my phone offers to open them in an app. They open black. When I look on my Mac, they appear fine in the Messages app.
Mac Mini M1 running latest Big Sur (Cannot be downgraded to Catalina) and AirMessage server beta 3.3.1.
Phone is a OnePlus 9 Pro running AirMessage 3.2.2
Connection is setup as manual with my primary address being the static local IP of my Mac and the fallback address being a DDNS address to my home network. Issue has occured while both on and away from my home network.
I will note also that a rare few times while an attachment initially displayed a filename and extension it suddenly properly loads. I don't know if your apps or the Mac is doing some kind of on the fly conversion but if so maybe something is failing? The only other wrinkle is that this appears to have started after getting an M1 Mac. I used to run Catalina on a hackintosh but decided to get a real mac after that PC died. So I am not sure if Big Sur itself is the culprit. If theres anything i can do to help isolate this further let me know.