BLZ51903003

Typically this error is caused by Blizzard services being in maintenance, however in some cases it can be caused by connection issues.

Before trying any of the following steps check the BlizzardCS Twitter. You can also check the Realm Status page (EU) / Realm Status page (US). If the service is offline, try again later. If these error codes occur outside of maintenance, follow these troubleshooting steps to resolve the issue.

1. Reset your network devices to make sure your router hasn't become flooded with data.
2. If you're using a wireless connection, optimize your internet connection to rule out a connection issue.
3. Release and renew your IP and flush your DNS to resolve any network conflicts.
4. Configure your security software's exception list to allow Blizzard applications to run.
5. Try closing background applications to resolve any software conflicts.
6. Update your drivers to resolve any compatibility issues.