> For the complete documentation index, see [llms.txt](https://docs.defguard.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.defguard.net/support-1/troubleshooting-guides.md).

# Troubleshooting Guides

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Before contacting support, please see if the answer cannot be found here.
{% endhint %}

Issues are grouped by component. Each linked page covers one specific problem.

### [Core](/support-1/troubleshooting-guides/core.md)

* [h2 protocol error from reverse proxy](/support-1/troubleshooting-guides/core/h2-protocol-error-from-reverse-proxy.md)
* [Unable to sign in with correct credentials](/support-1/troubleshooting-guides/core/unable-to-sign-in-with-correct-credentials.md)
* [User lost access to their 2FA methods](/support-1/troubleshooting-guides/core/user-lost-access-to-their-2fa-methods.md)
* [Enrollment URL Changed](/support-1/troubleshooting-guides/core/enrollment-url-changed.md)

### [Desktop Client](/support-1/troubleshooting-guides/desktop-client.md)

* [Failed to configure DNS (Linux)](/support-1/troubleshooting-guides/desktop-client/failed-to-configure-dns-linux.md)
* [Failed to parse IP address](/support-1/troubleshooting-guides/desktop-client/failed-to-parse-ip-address.md)
* [Disconnecting shows "Connection failed" (Linux / NetworkManager)](/support-1/troubleshooting-guides/desktop-client/disconnecting-shows-connection-failed-linux-networkmanager.md)
* [resolvconf not found (Debian)](/support-1/troubleshooting-guides/desktop-client/resolvconf-not-found-debian.md)
* [Unix socket does not exist (Linux)](/support-1/troubleshooting-guides/desktop-client/unix-socket-does-not-exist-linux.md)
* [Disconnected after MFA timeout](/support-1/troubleshooting-guides/desktop-client/disconnected-after-mfa-timeout.md)
* [Client connects but cannot reach VPN servers (MTU)](/support-1/troubleshooting-guides/desktop-client/client-connects-but-cannot-reach-vpn-servers-mtu.md)
* [Desktop client real-time / auto sync does not work](/support-1/troubleshooting-guides/desktop-client/desktop-client-real-time-auto-sync-does-not-work.md)
* [Windows client unable to connect](/support-1/troubleshooting-guides/desktop-client/windows-client-unable-to-connect.md)
* ["All traffic" connection issues](/support-1/troubleshooting-guides/desktop-client/client-all-traffic-connection-issues.md)
* [Windows installer exit codes](/support-1/troubleshooting-guides/desktop-client/windows-installer-exit-codes.md)
* [High disk usage](/support-1/troubleshooting-guides/desktop-client/high-disk-usage.md)
* [MFA location disconnected after X-time](/support-1/troubleshooting-guides/desktop-client/mfa-location-disconnected-after-x-time.md)
* [Unix socket permission error on connect (Linux)](/support-1/troubleshooting-guides/desktop-client/unix-socket-permission-error-on-connect-linux.md)

### [Mobile Client](/support-1/troubleshooting-guides/mobile-client.md)

* [Android "Failed host lookup" error](/support-1/troubleshooting-guides/mobile-client/android-failed-host-lookup-error.md)

### [Edge Component](/support-1/troubleshooting-guides/edge-component.md)

* [There was a network error. Can't reach Edge](/support-1/troubleshooting-guides/edge-component/there-was-a-network-error.-cant-reach-edge.md)

### [Gateway](/support-1/troubleshooting-guides/gateway.md)

* [No buffer space available](/support-1/troubleshooting-guides/gateway/no-buffer-space-available.md)

### No category

* [TOTP / email codes for MFA do not work](/support-1/troubleshooting-guides/totp-email-codes-for-mfa-do-not-work.md)
* [WebAuthn security keys](/support-1/troubleshooting-guides/webauthn-security-keys.md)
* [Can access VPN but not local network or internet](/support-1/troubleshooting-guides/can-access-vpn-but-not-local-network-or-internet.md)
* [How to verify the VPN is working](/support-1/troubleshooting-guides/how-to-verify-the-vpn-is-working.md)