Unable to access any site in FirefoxPortable - invalid error message received
This started occurring on my home PC (Windows10) on Friday 8 June 2018. When I fired up FirefoxPortable from my USB drive platform, and it opened my home tabs (office.com, google.com, wikipedia.org, and wiktionary.org), I saw the same result on each tab: "The owner of X has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. The site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate."