I've never used Bitwarden before, I just went to create an account for the first time and I see this message on both desktop (Librewolf) and mobile (Waterfox) on the signup page. What's BW trying to do here and what mechanism in the browser is blocking it?
Just a guess, but I would assume an ad/script blocker like uBlock Origin might be blocking a script they're trying to load?
Maybe that's it, I've just never seen a block presented this way before. And I'm not sure why it would have blocked this.
Their site might be using some form of analytics or tracking in a script, and could be the error handler on their end leads to a general error pop up like this, but again just a guess on my end