hi ruki114, does this happen in an account that is restricted by ms family safety settings? this would result in ms intercepting secure connections to some common sites like google, facebook, youtube and others. for this to work in firefox, you'd first have to install the certificate of ms family safety into the browser's trust store. click on this link, check the box to Trust this CA to identify web sites & confirm the change.

thanks for answering philipp but the link is broken, whats the full url?

Also I do not have ms family security settings enabled for my account, this is the only one in the family.

hi ruki114, sorry that this didn't work - this wasn't a tradtional link but should have opened a certificate installation window in your browser. alternatively you could have tried the manual steps described at https://support.microsoft.com/en-us/kb/2965142 in the section about firefox.

if you don't want to use that ms family feature anyway, please doublecheck that you have turned it off for your account: http://windows.microsoft.com/en-us/windows-10/turn-off-microsoft-family-settings

if this also does not work, could you tell us which anti-virus software you are using?

Thanks for the solution, it was the certificate not being seen. Did not know that firefox used a diff certificate store.