ContributionsMost RecentMost LikesSolutionsRe: "A required certificate is not within its validity period" - eight or more users can't connect My Windows 7 machine using a Firefox browser is able to load the digicert page without any warnings. However, I still get the same invalid required certificate error when trying to load gotomypc. Re: "A required certificate is not within its validity period" - eight or more users can't connect Same problem here. I can't connect from my Windows 7 machine but I am able to connect from my Windows 10 machine.