Please provide public link(s) (no password) that we can check out. No Personal Information Please !

https://vgy.me/

(free photo hosting site)

The error message reads:

An error occurred during a connection to vgy.me. The server uses key pinning (HPKP) but no trusted certificate chain could be constructed that matches the pinset. Key pinning violations cannot be overridden. Error code: MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem.

Did you try Firefox in safe mode?

We do not see this error code frequently, and often it goes unsolved:

https://support.mozilla.org/search/advanced?a=1&q=%22MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE%22&sortby=1&w=2

As you can see in past threads, we focus on whether there is an intermediary or "man in the middle" that may be causing the broken chain. Some of the most common ones are listed in this article: How to troubleshoot security error codes on secure websites.

I've tried everything - safemode still displays the message, my antivirus isn't listed (although I've gone through multiple root scans since this problem started just a few days ago - it used to work just fine, and then all of a sudden...) and I can't figure out how to add a certificate or if this is even possible in this case. Weirdly, the site displays just fine for me using Chrome. I prefer Firefox, but if it can't solve this issue, I may have to jump ship.

Thanks so much for all the hep, though, you guys are fantastic.

Try to rename/remove SiteSecurityServiceState.txt in the Firefox profile folder with Firefox closed.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

cor-el said

Try to rename/remove SiteSecurityServiceState.txt in the Firefox profile folder with Firefox closed. You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Sorry, I'm not clear on what exactly I ought to be doing. I found the file you mention, but don't know what to do from there. There does seem to be some type of information in it re: the website I can't access - is that what I should be editing?

Thank you so much for your time and expertise.

The instruction was to remove the file. Not edit. New files are created when needed.

If there is no mention of the involved domain in SiteSecurityServiceState.txt then there is no need to take action and you can skip my suggestion.

cor-el said

If there is no mention of the involved domain in SiteSecurityServiceState.txt then there is no need to take action and you can skip my suggestion.

There is mention of it though - a string of letters & numbers ad ten the site address is n all the txt when you up the folder. Some say delete tat folder entirely; some say rename; not sure what to do and am worried about breaking Firefox even worse. I'm so sorry to be a pain, I just can't understand how something works perfectly a few days ago and now this. I've contacted the site owners contacted my antivirus service, and now am here.I'm at my wit's end.

If you rename the file then you can undo this step or you can remove lines that reference a specific domain to keep the remainder of the file. Renaming a file with Firefox closed is a quick and easy test.