How to fix error code 51900101 in WoW Classic

WoW has been around for ages, received several expansions and updates, and delivers an in-depth look into the story and lore of Warcraft. Unfortunately, bugs, errors, and glitches have appeared throughout its life, including the 51900101 error code. If you've encountered this error as I have, then you may be wondering how to fix the error code 51900101 in World of Warcraft.

How to fix the World of Warcraft error code 51900101

To fix the WoW error code 51900101, delete your World of Warcraft cache folder. This will reset your UI, keybindings, add-ons, and more. I recommend saving your settings before deleting them so you can customize your preferences exactly how you had them before. After deleting your cache folder, the error should be gone. Here is how to delete your World of Warcraft cache folder.

Related: All WoW Games in Order – World of Warcraft Expansions List

• Open the World of Warcraft folder.
• Select Classic.
• Right-click on the Cache Folder.
• Select Delete.
• A new Cache Folder will appear in its place.

What is error code 51900101 in WoW

This error occurs most frequently in Classic and Burning Crusade Classic World of Warcraft. That doesn't mean you can't encounter it in other modes, but expect it more often in these. Sometimes the error can be caused by your internet or firewalls. If this is causing the problem and not your cache, you may need to adjust your firewall settings or upgrade your internet. You may need to restart your internet regardless, so start there before adjusting any settings.

For more information on World of Warcraft, check out WoW Realm Incompatible – How to Fix and What It Means and All World of Warcraft Classic Server Populations on Pro Game Guides.