Minecraft Launcher shows "Whoops! An unexpected issue occurred" when connected to the internet

Hi, The new Minecraft Launcher for Windows displays the error "Whoops! An unexpected issue occurred" shortly after opening the Java Edition page while connected to the internet.

The launcher initially loads, but after a few seconds, the interface switches to the error screen.

Interestingly, when I disconnect from the internet before launching it, the Java Edition page opens without displaying the error. However, online content does not load correctly.

The legacy Minecraft Launcher works normally on the same computer.

Steps to Reproduce

1. Connect the computer to the internet.

2. Open the new Minecraft Launcher.

3. Wait for the Java Edition page to load.

4. After a few seconds, the launcher displays "Whoops! An unexpected issue occurred."

Expected Result

The Minecraft Launcher should load the Java Edition page normally, retrieve online content, and allow me to launch the game.

Actual Result

The launcher displays an unexpected error screen and becomes unusable.

Troubleshooting Already Performed

• Reinstalled the Minecraft Launcher.

• Used Repair and Reset in Windows.

• Cleared the launcher web cache.

• Updated graphics drivers.

• Tested with and without a VPN.

• Tested using a different internet connection (mobile hotspot).

• Tested with two different Microsoft accounts.

• Tested using a new Windows user profile.

• Tested with a completely fresh .minecraft directory.

• Checked Windows system files using SFC and DISM.

• Checked Microsoft Store and Gaming Services.

• Tested the launcher Beta channel, but the error persisted.

• Checked Windows Event Viewer without finding a matching application crash.

• Confirmed that the legacy launcher works normally.

None of these steps resolved the issue.

Relevant Log Errors

The Chromium-based launcher interface reports:

TypeError: Cannot read properties of undefined (reading 'activeVersionId')
TypeError: Cannot read properties of undefined (reading 'title')

These errors originate from:

https://mojang/launcher/static/js/1301.10be1e32.bundle.js

The launcher logs also indicate successful authentication:

Response code: 200
Signed in to minecraft services

This suggests that authentication succeeds, but the launcher interface encounters a JavaScript error afterward. The exact cause is still unknown.

Environment

• Operating System: Windows 11 Enterprise

• Launcher Bootstrap Version: 2.6.2

• CEF/Chromium Version: 127.0.6533.120

• Affected Launcher: New Minecraft Launcher for Windows

• Working Alternative: Legacy Launcher for Windows 7/8

Additional Notes

The issue appears to be triggered by online initialization or content processing. It occurs across different Microsoft accounts, internet connections, and Windows user profiles.

I provided log files and screenshots

Please investigate whether the launcher is receiving unexpected data or failing to handle missing properties during online initialization.