Redownloading a fresh install file from the Discord website and restarting the process from scratch should resolve your issues and replace whatever Java Script file that was broken before.

We show you how to fix 'A fatal Javascript error occurred' issue while running or installing Discord on your Windows 11/10 PC.

On the next screen, find and delete the Discord folder. After deleting the folder, redownload and install the Discord program on your computer. Other Suggestions ...

If you’re running Discord on a Windows 7 machine, you can follow these steps to fix your fatal Javascript error: Click the Start button on the taskbar, or press the Windows key on the keyboard.