How to fix Discord error "A fatal Javascript error occurred" in Windows?

"A fatal Javascript error occured" is a box from the Discord desktop app's own start-up code: something stopped Discord from loading its main parts, and it quits. Windows itself is almost never the problem. Close every Discord process first, then delete Discord's two AppData folders and install it again, which is Discord Support's own fix.

Facts checked on 14 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2 with the Discord desktop app (Stable, PTB and Canary).

What "A fatal Javascript error occured" means in Discord

The Discord desktop app is built on Electron, a framework that runs a web app inside its own copy of Chromium. Electron's documentation says each app has a single main process, which runs in a Node.js environment and controls the app's lifecycle. Discord's start-up code, the part that checks for updates and loads the rest of the app, runs there.

When that code hits a problem it cannot handle, you get one of two boxes. Their titles are fixed text in the code, which is why everyone sees the same words with only the details changing.

How to read the error box and pick the right fix

The title only says who caught the problem. The useful part is below it. Before you click OK, take a picture of the whole box with Win + Shift + S, because the text disappears with the box and the next fix depends on it.

What causes the Discord fatal JavaScript error, from most to least common

Most often Discord's own files are damaged or out of step after an update that did not finish. Less often a copy of Discord is still running, a settings file points at something missing, or security software removed a file. Rarely a mod, malware, folder permissions or another program is behind it.

How to fix "A fatal Javascript error occured" in Discord

Fix 1 takes two minutes and Fix 2 is Discord Support's own fix, so most readers can stop there. Fixes 3 to 6 match a specific word in the error box. Fixes 7 and 8 are tests for when nothing in the box points anywhere.

Fix 1. Close every Discord process and start Discord again

2 minutesNo riskEveryone first, and especially when the box says currently running.

Discord keeps running in the notification area after you close its window, and its updater replaces the app's files at start-up. If an old copy is still running, the update collides with it. That is what Attempt to install host that is currently running reports.

1. Click OK in the error box after you have taken a picture of it.
2. Open the hidden icons arrow in the notification area. If the Discord icon is there, right-click it and choose the option to quit Discord.
3. Press Ctrl + Shift + Esc to open Task Manager and select Processes.
4. Find every Discord entry, under Apps and under Background processes. Select each one and choose End task. Discord often runs as several entries.
5. Restart the PC. Discord Support's own steps include a restart, and it also clears a stuck updater.
6. Start Discord once from the Start menu and wait for the update screen to finish before you click anything.

Step by step with Task Manager: Close a frozen app (Task Manager, Force Quit).

Fix 2. Delete Discord's two AppData folders and reinstall it

15 minutesLow riskThe error came back after Fix 1, or names a missing module or a damaged package.

This is the fix Discord Support gives for the JavaScript error. Discord installs per user in your AppData folders, and a normal uninstall can leave both behind, so a reinstall would load the same damaged files again.

1. Close every Discord process as in Fix 1. If any Discord entry stays in Task Manager, Windows will refuse to delete the folders.
2. Optional: uninstall Discord. Windows 11: Settings > Apps > Installed apps, the ... next to Discord, then Uninstall. Windows 10: Settings > Apps > Apps & features.
3. Press Win + R, type the line below and press Enter. Select the discord folder and delete it.

   %appdata%

4. Press Win + R again, type the line below and press Enter. Delete the Discord folder there too.

   %localappdata%

5. In the same Local folder, open SquirrelTemp if it exists and delete what is inside. It holds leftovers from earlier setup runs.
6. Empty the Recycle Bin and restart the PC.
7. Download a fresh installer from https://discord.com/download. Run DiscordSetup.exe with a normal double-click and let it finish and open Discord.
8. Sign in. Discord downloads its modules again on the first start, so wait until the update screen closes.

General uninstall steps for Windows 11 and 10: Uninstall a program or app in Windows. Use PTB or Canary? Their folders are discordptb and DiscordPTB, or discordcanary and DiscordCanary, and the same steps apply.

Fix 3. Rename Discord's settings file when the error names it

3 minutesLow riskThe at lines mention settings.json, pinned_update.json or setPinnedManifestSync.

In Discord's published start-up code, a setting called USE_PINNED_UPDATE_MANIFEST makes the updater read pinned_update.json before anything else. If that file is gone, start-up fails. If settings.json is missing, the code simply starts with default settings, so renaming it is safe.

1. Close every Discord process as in Fix 1.
2. Press Win + R, type this and press Enter:

   %appdata%\discord

3. If you cannot see file extensions, turn them on. Windows 11: View > Show > File name extensions. Windows 10: the View tab, File name extensions.
4. Rename settings.json to settings.json.old. Keep it: it is your way back.
5. If pinned_update.json is in the same folder, rename it to pinned_update.json.old as well.
6. Start Discord and let it update.

Fix 4. Check whether security software removed a Discord file

10 minutesLow riskYour antivirus showed an alert, or the box shows ENOENT on a Discord file.

If a security tool quarantines one file of a Discord module, the start-up code cannot load it and stops with this box. A reinstall then fails the same way if the tool removes the file again. Checking the tool's history tells you instead of guessing.

1. Open Windows Security from the Start menu and select Protection history.
2. Look for entries from the day Discord broke whose path is under AppData\Local\Discord or AppData\Roaming\discord.
3. If an entry is there, do not restore it blindly. Do the clean reinstall in Fix 2 so you get fresh files straight from discord.com, which Defender scans again.
4. If the fresh install is quarantined again, open Virus & threat protection > Manage settings and use Submit a sample manually to send the file to Microsoft for a second look.
5. With another antivirus, open its quarantine or history page and look for Discord paths in the same way.
6. To test once, pause real-time protection, start Discord, and turn protection back on right away: Turn off Microsoft Defender protection for a moment.

Fix 5. Remove a client mod or injected code from Discord

20 minutesLow riskThe at lines name a mod, or a file you never installed inside discord_desktop_core.

Client mods and some malware work by changing discord_desktop_core, the module Discord loads at start-up. Palo Alto Networks Unit 42 describes a stealer that kills Discord, writes its own script into that module and restarts it with Update.exe. Broken changed code ends in this error box.

1. Read the at lines in your picture of the box. Note any name that is not Discord, such as a mod, or a file with a random name.
2. If you installed a client mod yourself, remove it with its own installer, or just do Fix 2. A fresh install replaces discord_desktop_core with Discord's own copy.
3. If you never installed a mod, assume the change is malicious. Run a full scan and then a Microsoft Defender Offline scan: How to scan for malware with Microsoft Defender.
4. After the scan is clean, do the clean reinstall in Fix 2.
5. Then, from a phone or another PC you trust, change your Discord password and turn on two-factor authentication. Stealers of this kind are built to take your sign-in.

Fix 6. Start Discord once as administrator to test folder permissions

5 minutesLow riskThe box shows EPERM, EACCES, or operation not permitted.

Node.js describes EPERM as an operation that needs elevated privileges and EACCES as access forbidden by file permissions. A run as administrator shows whether permissions are the block. Discord installs per user, so it should not need this every day.

1. Close every Discord process as in Fix 1.
2. Type Discord in the Start menu, right-click it and choose Run as administrator.
3. Select Yes in User Account Control.
4. If Discord now opens, the problem is permissions. Close it, then do Fix 2 while signed in to your normal Windows account, so the new folders belong to you.
5. Do not set Discord to always run as administrator. Use it once, as a test only.

How to run a program as administrator on Windows 11 and 10: How to run a program as administrator or in compatibility mode. Older Discord help pages also suggest compatibility mode for Windows 7 or 8, but Discord has not supported those versions since 15 March 2024, so we do not recommend it.

Fix 7. Test Discord in a new Windows user account

15 minutesNo riskYou reinstalled cleanly and nothing in the box points to a cause.

Discord keeps everything inside your user profile. A new account has fresh AppData folders and no programs that start with your sign-in, so it separates a problem in your profile from one in Windows or other software.

1. Create a local test account and sign in to it: Create a new user account to test a problem.
2. Download Discord from discord.com in the new account and install it there.
3. If Discord works in the new account, the cause is in your old profile. Repeat Fix 2 carefully there, or move to the new account.
4. If Discord fails in the new account too, the cause is system-wide. Go to Fix 8.

Fix 8. Find conflicting software with a clean boot

20 minutesLow riskDiscord fails in every Windows account even after a clean reinstall.

Overlays, game boosters and some security suites load into other programs at start-up. A clean boot starts Windows with only Microsoft services, so if Discord opens then, one of the switched-off programs is the cause.

1. Open System Configuration. Select Search on the taskbar, type msconfig and select System Configuration from the results.
2. Hide Microsoft services. On the Services tab, select the Hide all Microsoft services check box. Only services from other companies stay in the list.
3. Disable the remaining services. Select Disable all, then select Apply.
4. Open Task Manager. On the Startup tab of System Configuration, select Open Task Manager.
5. Disable the startup apps. On the Startup apps tab in Task Manager, select each item whose status is Enabled and select Disable. Write down or take a screenshot of the items you disable: you need the list to turn them back on.
6. Confirm the changes. Close Task Manager. On the Startup tab of System Configuration, select OK.
7. Restart and test. Restart the PC. Windows now starts in a clean boot environment: try again the thing that failed (run the app, install the update, uninstall the program).

These steps were written for Windows 11 25H2 and 26H2. The full page with the other versions and what each result means: How to perform a clean boot in Windows

When Discord opens in the clean boot, turn the services back on in small groups and restart each time. The group that brings the error back holds the program to update or remove.

Still getting the Discord JavaScript error? What to collect and send

Discord Support asks you to contact it at dis.gd/contact if the error stays after the clean reinstall. A good report saves a round of questions. Check discordstatus.com first: an outage shows up there.

• The whole error box: your picture of the title, the Error: line and every at line.
• Your Discord build: the version shown under Discord in Installed apps, for example 1.0.9183, and whether it is Stable, PTB or Canary.
• The setup log, if the box appeared during setup: %LocalAppData%\SquirrelTemp\SquirrelSetup.log. Squirrel's documentation names this file as the log of the first install.
• Your Windows version: press Win + R, type winver, press Enter.
• What you already tried, in order, including Fixes 1 and 2 and the result of the new account test.

How to keep the fatal JavaScript error from coming back

If you need Discord while you work on the desktop app, open it in your browser at discord.com/app. It uses the same account and does not depend on the files in AppData.

Frequently asked questions

Is the fatal JavaScript error in Discord a virus or a problem with Windows?

Usually neither. The box comes from Discord's own start-up code, and the most common reasons are a damaged update or a copy of Discord still running, which Fixes 1 and 2 clear. Windows only matters when it blocks Discord's folders. A virus is a real but rare cause: some Discord token stealers change the discord_desktop_core module, and a broken change can end in this box. If the at lines name a file you never installed, run a Microsoft Defender scan before you reinstall (Fix 5).

Will I lose my messages or servers if I delete the Discord folders?

No. Messages, servers, friends and Nitro are stored on your Discord account, not on your PC. Deleting %AppData%\discord signs you out on this computer and resets local app settings, such as keybinds, startup behavior and some voice settings. Deleting %LocalAppData%\Discord removes only the program, which the installer downloads again. Make sure you know your password and have your two-factor codes before you start, because you will need to sign in again.

Is "discord java error" the same as the JavaScript error?

People often search it that way, but Java and JavaScript are different languages. Discord does not use Java, and installing or updating Java will not change anything. If your box says JavaScript, follow the fixes on this page. If you really see an error from Java, it comes from another program, such as a game or launcher that uses Java, and Discord is not involved. Check the title bar of the error box to see which program showed it.

Does the Discord fatal JavaScript error happen on Windows 11?

Yes. The error comes from the Discord app, so it looks the same on Windows 11 and Windows 10, and the fixes are the same. The only differences are the menu names in Settings, which the steps give for both. Discord needs 64-bit Windows 10 or later: it dropped Windows 7, 8 and 8.1 on 15 March 2024 and 32-bit Windows on 15 June 2024. Windows 10 itself left Microsoft support on 14 October 2025.

Can I use Discord while the desktop app shows this error?

Yes. Open discord.com/app in Chrome, Edge or Firefox and sign in with the same account. The browser version does not use the desktop app's files, so the error does not affect it. You can also install the PTB test build from discord.com/download. It installs to separate discordptb and DiscordPTB folders, so it often starts while the Stable build is broken. Discord says test builds have more bugs, so use PTB as a stopgap only.

Why does the error come back after I reinstall Discord?

A normal uninstall can leave %AppData%\discord and %LocalAppData%\Discord in place, and the next install picks up the same damaged files. Delete both folders as in Fix 2. Other reasons it returns: a Discord process was still running during setup, security software removes the same file again (Fix 4), or a mod or malware rewrites discord_desktop_core after every install (Fix 5). The Error line in the new box tells you which one it is.

Should I keep Discord set to run as administrator?

No. Discord installs into your own user folders and does not need administrator rights in normal use. Starting it as administrator once is a useful test for EPERM or EACCES errors (Fix 6). If it works, reinstall Discord as your normal user so the folders belong to you, and start it normally. A program that always runs elevated can change more of your system if something goes wrong inside it, so keep elevation for tests.

What does "Uncaught exception" mean in a Discord error?

It means an error happened in Discord's code and nothing in that code was written to handle it, so the last safety net caught it. That safety net is the box titled A JavaScript error occurred in the main process. Everything after Uncaught exception: is the stack trace: first the error itself, then the at lines listing the functions and files that were running. Read the first line and the file paths, then use the table under "Read the error box" to pick a fix.

What does a Discord "fatal error" without JavaScript in the title mean?

This page covers the two JavaScript boxes Discord shows at start-up. Discord also shows other messages, such as an installation failed message during setup or a banner that says the installation is corrupt. Discord Support's answer for a corrupt installation is the same clean reinstall as Fix 2: close every Discord process, delete both AppData folders, restart and install again. If your box has a different title, search for its exact title and Error line.