Getting this error for a while now but their status page (https://status.proton.me/) doesn't show any issue so far:
"Something went wrong
We couldn't load this page. Please refresh the page or check your internet connection.
Error: Servers are unreachable. Please try again in a few minutes"
To anyone from Proton: It would, perhaps, be a good idea to implement a notice in the app version, giving some form of clue when this happens. It's easy to hit send and carry on, and not realize there's an issue.