Fix ‘LUA Error’ in Word of Warcraft on Windows

Some Word of Warcraft users are reporting that they regularly see an ‘LUA Error‘ pop-up when they boot up the game saying that some of the installed add-ons are malfunctioning. This issue is confirmed to occur on Windows 7, Windows 8.1, and Windows 10.

What is LUA?

Before we get to the causes and the fixes regarding this LUA pop-up error, it’s important to understand what exactly is LUA and how it’s used inside Word of Warcraft.

LUA is a script-based programming language that adds modularity to programs via embedding. This is the preferred programming language used by community modders to create custom content for Word of Warcraft.

After investigating this particular issue thoroughly, it turns out that there are several different underlying causes that might cause this error pop up. Here’s a shortlist of potential culprits that might be responsible for this error:

Now that you know the most likely culprits that might be causing this error code, here’s a list of verified fixes that other affected users have successfully used to get to resolve these pesky LUA pop-up errors:

1. Reloading the interface

If the problem is caused by a glitch or a situation where not every addon element is loaded along with the base WOW game, you should be able to fix the issue by forcing the game to reload the main game interface using a console command.

This problem is confirmed to occur by a lot of users that we’re previously getting the ‘LUA Error‘ whenever they launched the game. Keep in mind that this error is not necessarily a symptom that there’s an underlying issue causing the error pop up.

Most likely, the error occurs because some of the add-on code is outdated and is no longer fully integrated with the base game.

In most cases, you should be able to make the error prompt go away by reloading WoW’s user interface utilizing the built-in game console.

To reload Wow’s interface, simply open the chatbox, type the following command, and press Enter to enforce it:

/reload

Note: This method might not work with the latest versions of WOW if the command attached to it is protected, but it should work with the Vanilla version of Word of Warcraft.

If you already tried this fix and you’re still being prompted by the same LUA error, move down to the next fix below.

2. Reset Wow’s Interface & uninstall the addon manager

If a simple reload didn’t fix the interface LUA error popup, the next step you should take is to reset the WOW interface completely to clear any code remnants left behind by a previously uninstalled addon or by your addon manager.

While you do this, it’s important to also uninstall the addon manager that you’re currently using and clear the addon files located in the 3 main Word of Warcraft directories that might be currently storing.

Follow the instructions below to reset Wow’s User interface and eliminate the LUA error prompt:

1. First things first, start by closing Word of Warcraft and the launcher that you use to start the game.
2. Next, press Windows key + R to open up a Run dialog box. Inside the Run box, type ‘appwiz.cpl’ and press Enter to open up the Programs and Features menu.

   

   Note: If you’re prompted by the UAC (User Account Control), click Yes to grant admin access.

3. Inside the Programs and Features menu, scroll down through the list of installed applications and locate your WOW addon manager – Most commonly Ajour, CurseBreaker, InstaWoW, WowUp, or Overwolf.
4. Once you manage to locate the entry associated with your active WOW addon manager, right-click on it and choose Uninstall from the context menu that just appeared.

   

5. Inside the uninstallation screen, follow the on-screen prompts to complete the uninstallation process. After the operation is complete, reboot your computer and wait for the next startup to complete.
6. After your computer boots back up, navigate to the location where you installed World of Warcraft. Unless you installed the game in a custom location, you’ll find it inside one of the following locations:

   C:Program Files /(x86)World of Warcraft
   C:Program Files / World of Warcraft
   C:Users[username]PublicGames / World of Warcraft

   Note: If you can’t remember the custom location where you installed the game, right-click on the shortcut you use to launch the game and click on Open file location from the context menu that just appeared.

7. Inside the Word of Warcraft folder, click on the game version that you’re experiencing the LUA errors in.
8. Next, go ahead and rename the Cache, Interface and WTF folders to the following:

   Cache: Cache_Old
   Interface: Interface_Old
   WTF: WTF_Old

   Note: This is important since it will force the game to create new folder equivalents for these 3 locations. And in case this doesn’t fix the issue, you can always go back and remove the ‘_old’ extension to re-load the old addon files.

9. Launch World of Warcraft once again and see if the issue is now fixed.

If the same problem is still occurring after your uninstalled your WOW addon manager and prevented the interference with any old addon files, move down to the next potential fix below.

3. Resetting the WOW console variables

If reloading or resetting the main WOW interface was not effective in your case, you should proceed by resetting every WOW console variable that is currently in use.

This will be effective in those situations where you previously installed and ran multiple add-ons with different parameters that might have ended up conflicting with each other.

A lot of users dealing with LUA errors when launching World of Warcraft have confirmed that the problem was fixed after they ran a series of commands inside the in-game chatbox aimed at resetting every custom variable and enforcing the default variables once again.

Here’s a quick guide on how to do this:

Important: Before you start this operation, understand that if you’re running multiple add-ons at this time, resetting the console variables will also delete all addons – This might not be a desirable outcome if you don’t want to be forced to reinstall everything all over again.

1. Open World of Warcraft and pop-open the in-game chatbox menu once you get to the initial screen.
2. Type the following commands in order and press Enter after each one to effectively reset any previously established WOW custom variable:

   /Console Cvar_reset
   /console cvar_default

   Note: If you receive a permission error once you enforce these two commands ignore it as it’s perfectly normal.

3. Restart the game and see if the LUA error has been resolved.

4. Uninstall the Cartographer Add-on (or other outdated add-ons)

As it turns out, you can also expect to see this error code if you are trying to launch the game with an outdated add-on that is no longer compatible with the game version.

This is very common with the Cartographer add-on and a few others that have stopped receiving support from their developers.

The instructions for uninstalling these problematic addons will be different depending on the add-on launcher that you’re using.

If you’re not currently using the Cartographer mode and you have no idea which of your installed mods are causing the issue, our recommendation is to uninstall every addon before adding them again (one by one) to figure out which one is causing the LUA error.

In any case, once you manage to uninstall the outdated mode, reboot your game and see if the problem went away for good.

If none of the fixes so far have worked, move down to the final potential fix below.

5. Disable LUA Error Prompts

If you would rather hide the errors rather than figuring out their root cause, you can simply input a command to prevent them from showing up every time you launch Word of Warcraft.

Of course, this will not fix the root cause of the issue, it will only prevent the error prompts from showing up.

This is enough if you can still use the add-ons without any underlying issues.

Here’s a quick step-by-step guide that will allow you to disable the LUA Error prompts from appearing when you launch World of Warcraft:

1. Open World of Warcraft and close the error pop-up when it comes on screen.
2. Next, open the chatbox and type the following command, and press Enter to effectively prevent any LUA errors from appearing on screen ever again:

    /console scriptErrors 0

3. Restart World of Warcraft and you should no longer see any LUA pop-up errors appearing on screen.
   Note: If you ever want to enable the pop-up errors again, simply type the following command inside the console /console scriptErrors 1.