I noticed things were not syncing completely, so I signed out of sync intending to sign back in. Problem is I run into the following error message when I try to sign back in

   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."

I am having a couple different issues here. First is after I refreshed Firefox due to sluggish performance I noticed things were not syncing completely, so I signed out of sync intending to sign back in. Problem is I run into the following error message when I try to sign back in Secure Connection Failed An error occurred during a connection to accounts.firefox.com. Peer's certificate has an invalid signature. (Error code: sec_error_bad_signature) 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." I've uninstalled and reinstalled Firefox multiple times trying to cure this problem but it persists. So I thought it might be a bug in the current release of the software. So I tried downloading a beta and a Nightly release. This is when I run into my next problems. I cannot get either of these early releases to even install. The beta release 40.0b6 begins to install but gives me a download interrupted message right towards the end of install. While other early releases 40.0b4, 40.0b7, 42.0a1 deny me access with a message of: Windows cannot access the specific device, path or file. You may not have the appropriate permissions to access the item. I am running an Insider build of Windows 10 but the issue is isolated to one machine and does not pop up on other machines running nearly identical configurations and only popped up recently. It would be great if I could at least get sync to work as I am lost without it!