Please create a specific “Unable to connect” page
The support help desk is kept busy with messages like “I can't connect to aaaaaaaaaaaaaaaa.onion” when the problem is that the hidden service is simply down. Our default answer is currently in the like of “Can you connect to the Tor Project's website through http://idnxcnkne4qt76tg.onion/ ? Then Tor is working and that hidden service is simply down. We have no control over it anyway.”
It would probably be good to try to improve the “Unable to connect” page to help users understand what's happening when they can't reach a hidden service.
The current “Unable to connect” page says:
Unable to connect
Firefox can't establish a connection to the server at aaaaaaaaaaaaaaaa.onion.
- The site could be temporarily unavailable or busy. Try again in a few moments.
- If you are unable to load any pages, check your computer's network connection.
- If your computer or network is protected by a firewall or proxy, make sure that TorBrowser is permitted to access the Web.
The first statement is misleading for hidden services. This is likely due to the different behaviour of hidden services: without Tor, Firefox issues DNS lookups first and by default will not display this page when a domain is unresolvable. It will only display it after the resolution, when trying to connect to the IP address. For hidden services, we can't make the difference, and we might want to make that clearer.
The last statement is confusing no matter what. At this stage, we know if the Tor Browser is able to reach the Tor network or not, so it might make sense to simply remove it.
This ticket is also related to #8000 (moved).