# Known issues and limitations in Tor Browser

Desktop
Android

- 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. 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.
- 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.
- Web Authentication (WebAuthn) and Universal 2nd Factor (U2F) (i.e. YubiKey) support is disabled in Tor Browser.
- Images uploaded on Tor Browser (Desktop and Android) are randomized.
- Running multiple instances of Tor Browser at the same time is not recommended. On many platforms this may not work as expected and can cause errors or unexpected behavior.
- Issues with making Tor Browser your default browser. There are methods for setting Tor Browser as your default browser, but those methods may not work always or in every operating system. Tor Browser works hard to isolate itself from the rest of your system, and the steps for making it the default browser are unreliable. This means sometimes a website would load in Tor Browser, and sometimes it would load in another browser. This type of behavior can be dangerous and break anonymity.

### Issues in the latest stable release

Whenever we release a new stable version of Tor Browser, we publish a blog post that details new features and known issues.
If you started experiencing problems after an update, check blog.torproject.org for the post about the latest stable release.

If your issue isn't listed there:

- Check the Tor Browser issue tracker.
- If it hasn't been reported, please open a GitLab issue describing what you're experiencing.

At the moment, there are some features which are not available in Tor Browser for Android, but are currently available in Tor Browser for desktop.

- You can't see your Tor circuit. #200
- Tor Browser for Android does not connect when moved to the SD Card. #31814
- You can't open onion addresses that requires Client Authorization #201
- 'New Identity' feature is not available on Tor Browser for Android. #28800
- 'Onion-Location' feature is not available on Tor Browser for Android. #151