• Tor needs your system clock (and your time zone) set to the correct time.

  • Antivirus or malware protection blocking users from accessing Tor Browser. Sometimes these also pop up with false positives regarding malware and/or vulnerabilities. You can read more about this on our Support Portal. The following antivirus and firewall software have been known to interfere with Tor and may need to be temporarily disabled:

    • Webroot SecureAnywhere
    • Kaspersky Internet Security 2012
    • Sophos Antivirus for Mac
    • Microsoft Security Essentials
    • Avast Antivirus

  • VPNs also tend to interfere with Tor and need to be disabled. We also do not recommend using VPN and Tor together unless you're an advanced user who knows how to configure both in a way that doesn't compromise your privacy. You can find more detailed information about Tor + VPN at our wiki.

  • Videos that require Adobe Flash are unavailable. Flash is disabled for security reasons.

  • Tor can not use a bridge if a proxy is set.

  • The Tor Browser package is dated January 1, 2000 00:00:00 UTC. This is to ensure that each software build is exactly reproducible.

  • Issues with making Tor Browser as your default browser.

  • If Tor Browser was working before and is not working now (especially after a re-install or an update), your system may have been hibernating. A reboot of your system, in that case, will solve the issue.

  • Tor won't start on Windows when the folder path contains non-ascii characters.

  • BitTorrent is not anonymous over Tor.