Tor Browser 5.5.3 is released

Excuse me for my crippled sentence
The sentence:
"Does, or can Torbrowser warn for this "ssl interception" or must a user always on every website do a manual ssl encryption to check the validity of the offered certificate in the browser-lock?
Had to be more like this:
Does, or can Torbrowser warn for this "ssl interception" or must a user always on every website do a manual ssl check by manually checking the validity of the offered certificate in the browser-lock? Therefore looking at "more information", "View certificate" and then find out if the certificate really is belonging to / assigned to the owners of the website you are visiting.

Now, the reason for this question is that people who are against Tor try to convince others that Tor is a unsafe technique because it is not protected to MitM interception even on encrypted connections.
The idea is that MitM attacks can take place on an exit node by using another certificate so the user actually sees a lock in the url bar but when manually checking could find (or not) out that this is not the right certificate but simply an intermediate certificate of the interceptor.

So, what I would know if it's is possible to intercept an encrypted connection on an exitnode and decrypt this (I hope not) while letting the user believe that it is using the original encrypted connection because it will see a lock in the url bar.

I see over and over again people saying that this kind of interception attack is possible and therefore that using Torbrowser over the Tornetwork is unsafe because one never could know (directly) if the information the Torbrowser user is sending over a fully encrypted connection is intercepted.
Although I got the impression that this is probably not possible, I would rather see a clear answer to that matter so that if people start using these kind of "Tor is not secure reasons" again we could refer to the answer on Torproject space.

I'm not familiar with this specific company, but the way these things generally work is that the proxy generates its own certificate for every site you attempt to visit. So unless you have the proxy's CA certificate installed in your browser you'll see a big scary error message.

If you (a Tor user) are behind such a proxy, you will probably find that you're unable to connect to the Tor network at all, except possibly via pluggable-transport bridges.

If an exit node is behind such a proxy, then anyone who uses that exit node (assuming they're using the Tor Browser) will see an error message when they try to visit an HTTPS site. If you find such an exit node you should report it so it can be blacklisted.

Window maximizing was finally fixed! After months and months and months of ignoring a basic usability problem.