Here's what is happening for me, and it happens a lot.
On facebook, have clicked on the link to upload a photo. Photo starts to upload, and I start to write a caption. Opera crashes.
After Opera restarts, photo uploads and all is fine.
Does not happen every time but possibly 1 in 4.
Update stream: Stable
System: Mac OS X 10.12.6 64-bit
Opera is using a port not assigned as a standard web browsing port to check for updates, and your firewall probably blocks it. Check the blog or here in the forums - or subscribe to the blog's newsfeed - to see when a new version comes out and download it manually. (You can even install the new version while Opera is running, but you'll have to restart Opera once the installer finishes.)
I have seen that message once or twice when there were network issues between here and Norway, but never for very long.
Thank you sgunhouse