Error when opening a page after login

[xenarulz]

Hello, I have a problem that's difficult to explain.
Basically, my employer has a outlook express-based webmail for its employees and we can access it from any place.
I tried today for the first time with Pale Moon but after I logged in, the page where I usually see the incoming mail didn't open. Instead, I got a message that it wouldn't be opened because it wasn't possible to verify the authenticity of the data coming from it.
I tried with Firefox and it opened immediately.
What could be the problem? Some certificate I should import in PM?
If there is something more I can do to identify the issue let me know, but I cannot give you the login data to try to replicate it...
Thanks!

[Moonchild]

It would help if you provide the exact error message you get.

[Pallid Planetoid]

To reiterate - the "exact error message you get" would be helpful because I'm assuming you are trying this at your work-place. On that point, have you tried doing the same thing at home, that is accessing the mail at home using Pale Moon? I'm thinking that there may be some security software (Firewall of some kind) at work that could be interfering.

[xenarulz]

To reiterate - the "exact error message you get" would be helpful because I'm assuming you are trying this at your work-place. On that point, have you tried doing the same thing at home, that is accessing the mail at home using Pale Moon? I'm thinking that there may be some security software (Firewall of some kind) at work that could be interfering.

I tried only at home, because at work we have preinstalled sw and I can't installe Pale Moon.
The exact message is (translated):

Secure connection failed
The connection with ..... was interrupted while page was loading
The page you're trying to view cannot be shown because it is not possible to verify the authenticity of the received data.
Contact the website owner to inform him of the problem.

[Nigaikaze]

Secure connection failed
The connection with ..... was interrupted while page was loading

viewtopic.php?f=24&t=6262

[xenarulz]

Thanks. Solution 2 solved it. I informed the server admins but I have little hope.
Question: the workaround says

IMPORTANT for Pale Moon 27.2 and later: You must also allow unrestricted fallback to weak ciphers for the site: find security.tls.insecure_fallback_hosts and double-click it, then add the hostname of the site you want to connect to (e.g. www.insecurebank.com) to that preference. You can add multiple sites if needed, separated by a comma (e.g. www.insecurebank.com,www.anotherbadsite.com)

It works even without doing this thing, why is it important to do it? What is it for? (I ask only because I want to learn, not to question what is being said)