"You will have to acquire the root certificate of this proxy and install it in Firefox to prevent such an untrusted message. If you have this certificate in IE or Google Chrome then export it and import in Firefox. You can inspect the certificate chain in those browser to see how they link it to a built-in root certificate. You need to set the trust bit to trust this certificate for web pages. "

Thanks cor-el for providing the solution.

Check here

• https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

This is not proxy. It is a vendor test environment that I need to do some functional troubleshooting on. I am spoofing DNS for my prod domain to the IP of the test system. The test SSL cert does not match the name of the domain I am spoofing. I need to have SSL enabled but have no way to match the domain name to the cert. Is there a way to temporarily disable or bypass the FF 22.0 "Untrusted Connection" warning?

The answer at : https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

This seems to refer to an earlier version of FF which provided an easy "I understand the risks" bypass option. FF 22.0 seems to have moved or removed the bypass option.

the button is only missing in certain situations (like when the untrusted page is embedded within an iframe)...

In this case, when the certificate presented does not match the domain being called the "I understand the risks" button is missing. Is there some other way to work around this? Is it a new "feature" that users have absolutely no way to bypass this warning? Or is the lack of a way to bypass the warning a bug that needs to be fixed? The answer may depend on whether FF is intended only for users who need to always be protected or if it also intends to be a tool that developers can use for troubleshooting in complex environments.

also in cases where there is a certificate missmatch the "i understand the risks"-button is normally not hidden (see https://www.lmsvc.com/ as an example). this is only happening in exceptional circumstances, like an encrypted site embedded as iframe or when HSTS is at play if i'm not mistaken...

there's no way of generally switching off the certificate error messages, because of the impact on security this would entail.

I also have this problem. The problem isn't an "untrusted" message, I don't care. The problem is that the "I understand the risks" option is gone.

I have the latest firefox, my system times are fine, etc etc. This happens both on my Mac OS X at home and my Windows 7 system at work. It only started i the last couple of months or so.

It is irritating. It interferes at work and I'm forced to use chrome. Stop taking options away from us. Warn us about things, fine. But stop playing big brother.

Give me back my option to proceed!