Error: WOW51900328

If you experience problems with World of Warcraft after patching, first check the Realm Status page to see if your realm is currently online. If your realm is online, try the following:

1. Restart your computer to resolve problems caused by programs and services running in the background
2. Reset your user interface to make sure your files and addons are not corrupted
3. Configure your security software's exception list to allow Blizzard applications to run
4. Configure firewall and proxy settings for World of Warcraft

If the previous troubleshooting steps didn't resolve the problem, you can ask the Blizzard player community for help on the tech support forums (if available) or other community gaming sites. Local computer or network technicians may also be able to help if you've exhausted all other resources.