Zoom Error Code 104 — What It Means & How to Fix It

What Does This Error Mean?

Zoom Error Code 104 means Zoom cannot establish a network connection. This is a connectivity error — either your internet is down, Zoom is blocked by a firewall, or Zoom's own servers are having a problem. Checking your internet connection and firewall settings resolves this in most cases.

Affected Models

Zoom on Windows 10
Zoom on Windows 11
Zoom on macOS

Common Causes

Your internet connection is down or unstable
A firewall (Windows Firewall, router firewall, or network firewall) is blocking Zoom
A VPN or proxy is interfering with Zoom's connection
Zoom's servers are temporarily experiencing an outage
Network security software on your computer is treating Zoom as a suspicious application and blocking it

How to Fix It

Check if other apps and websites work. If nothing on your computer can access the internet, restart your router and modem first.

Unplug the router and modem from power, wait 30 seconds, then plug them back in.
Check Zoom's server status at status.zoom.us. If there is an active incident listed, the problem is on Zoom's end — wait and try again.

Zoom has a public status page that shows real-time information about server issues.
Check that Zoom is allowed through Windows Firewall. Go to Control Panel > Windows Defender Firewall > Allow an app. Find Zoom and make sure both Private and Public boxes are checked.

If Zoom is not in the list, click 'Allow another app' and add the Zoom executable.
Disable any VPN or proxy you are using, then retry Zoom. If it works without the VPN, the VPN is blocking Zoom.

Some VPNs block video conferencing apps. Try a different VPN server, or add Zoom to your VPN's split-tunneling exclusion list.
Try using Zoom's web client as a temporary workaround. Go to zoom.us and join the meeting through your browser without the app.

The web client works even if the desktop app is blocked, since it uses your browser's network settings.

When to Call a Professional

Error Code 104 is almost always a network or firewall issue you can fix yourself. If you are on a corporate or school network, a network administrator may have blocked Zoom — ask them to whitelist it. If the error persists on your personal home network after all steps below, contact your internet provider.

Frequently Asked Questions

Does Error 104 affect others in the meeting or just me?

Only you. Error 104 is a connection problem on your end — it does not affect other participants. Other people in the meeting can continue without you. Once you fix your connection, you can rejoin the meeting.

Zoom worked fine yesterday and now shows Error 104. What changed?

A few things could have changed: your router may have restarted and assigned different network settings, a Windows update may have reset your firewall rules, or an antivirus update may have started blocking Zoom. Check your firewall settings and make sure Zoom is still listed as an allowed app.

Can I join a Zoom meeting without the app when I get Error 104?

Yes. Every Zoom meeting invite includes a link like zoom.us/j/XXXXXXXXX. Open that link in Chrome or Edge and click 'Join from Your Browser' to join without the desktop app. This is a useful backup when the app has connection problems.