Marvel Rivals has taken the gaming world by storm, offering players the chance to jump into the action with their favorite superheroes. However, nothing kills the momentum faster than being met with an unexpected login error. If you are struggling to jump into a match because of the dreaded Marvel Rivals error code 21, you are certainly not alone. This connection-related issue can be frustrating, but in many cases, it is easily resolved with a few simple tweaks to your setup.
What Is Marvel Rivals Error Code 21?
In most instances, the Marvel Rivals error code 21 is a communication error between your client and the game’s servers.
It often indicates that the authentication service or the game server is failing to handshake with your device correctly.
While this can sometimes be an issue on the developer's end—particularly during periods of high server load or maintenance—it is frequently caused by a local networking hiccup, outdated software, or corrupted files on your machine.
How to Fix Marvel Rivals Error Code 21 (Step-by-Step)
Before you get too worried, follow these proven troubleshooting steps to fix the issue and get back to the battlefield as quickly as possible.
1. Check the Official Server Status
The first and most important step is to determine if the problem is on your end or theirs.
If the game servers are down for maintenance or experiencing a massive outage, no amount of tweaking on your PC will fix it.
Check the official Marvel Rivals Twitter (X) account, their Discord server, or third-party status tracking websites to see if other players are reporting the same issue.
If there is a global outage, you will simply need to wait for the developers to restore service.
2. Restart Your Game and Launcher
It sounds simple, but a quick restart is often the cure for temporary handshake errors.
Close the Marvel Rivals game client completely, as well as the launcher you are using (such as Steam or the Epic Games Store).
Wait about 30 seconds to ensure all background processes have fully terminated, then relaunch the game.
This forces a fresh connection attempt, which can often resolve the authentication error.
3. Check Your Internet Connection
Since error code 21 is a connection error, your local internet stability is the prime suspect.
Try power-cycling your router by unplugging it for 30 seconds and plugging it back in.
Furthermore, if you are playing on a Wi-Fi connection, try switching to a wired Ethernet cable if possible.
Wi-Fi can suffer from packet loss or latency spikes that trigger authentication timeouts, leading to the error code appearing.
4. Verify Game Files
Sometimes, a corrupted file is the root cause. A missing or damaged configuration file can prevent the game from communicating with the login servers. If you are using Steam, right-click Marvel Rivals in your Library, select Properties, go to the Installed Files tab, and click Verify integrity of game files. For Epic Games, click the three dots next to the game title, select Manage, and then click Verify. The launcher will automatically scan for errors and replace any corrupted files.
5. Update Graphics Drivers and Windows
Outdated drivers can sometimes create compatibility issues that manifest as network errors.
Ensure your NVIDIA, AMD, or Intel graphics drivers are updated to the latest version.
Additionally, check for pending Windows updates.
A system that is out of date may lack the necessary security protocols or network libraries required for the game to function properly.
When to Contact Support
If you have followed all the steps above and are still encountering the Marvel Rivals error code 21, the issue might be deeper, potentially involving your specific account or a firewall blocking the game's traffic.
At this point, it is best to submit a support ticket via the official Marvel Rivals website.
Be sure to include your error code, a screenshot if possible, and a list of the troubleshooting steps you have already attempted.
This will help the support team provide a faster, more effective solution for you.
Frequently Asked Questions (FAQ)
Is Marvel Rivals error code 21 a permanent ban?
No, error code 21 is typically a connectivity or authentication issue, not a sign that your account has been banned.
Does restarting my router fix error code 21?
Yes, restarting your router can resolve local network handshake issues that often trigger this specific error code.
Why does error code 21 happen during peak hours?
It is often caused by server congestion.
If the servers are overloaded, your client may fail to authenticate, resulting in error code 21.
Should I reinstall the game to fix this error?
Only as a last resort.
Try verifying the game files through your launcher first, as this is faster and less intrusive than a full re-installation.
Written by: Joshua Adams
Read also: Fixing GeForce Now Error Code 0xc2720018: The Ultimate Troubleshooting Guide
