Unable to sign in to Minecraft

[bruegge99]

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal
• I have ensured my Modrinth App installation is up to date

What version of the Modrinth App are you using?

0.10.19

What operating systems are you seeing the problem on?

Windows

Describe the bug

I installed the Modrinth app. As soon as I click on Log In, this window appears with the following debug information:
Minecraft authentication error: Failed to deserialize response to JSON during step GetDeviceToken: EOF while parsing a value at line 1 column 0. Status Code: 400 Bad Request Body:
However, the Microsoft login window doesn’t even appear — instead, it immediately shows the window you can see in the attachment. Nothing happens when I click the “Try another account” or “Try signing in again” buttons.

Everything works fine in the official Minecraft Launcher. I can log in with my Microsoft account there and play without any issues.

I already tried synchronizing the PC time / time zone — same error.
I wiped my whole PC and reinstalled Windows — same error.

Steps to reproduce

1 Open Modrinth
2 Click Log In
3 Error appears

Expected behavior

I expected an Sign In window where i can sign in with my microsoft account

Additional context

No response

[bruegge99]

I tested it with the old version of Modrinth (0.6.3). There, I can log into my Microsoft account without any problems and at least install and launch the older versions of Minecraft — only versions newer than 1.20.5 don’t work; a Java error appears.

[Hallskii]

Hey, I wasn't able to reproduce this and it could be an issue specific to your machine. Can you create a support ticket with our team and see if they can get to the bottom of it for you? https://support.modrinth.com/en/ (bottom right)

Closing for now

[ped0rooo]

I had this problem too. I tried everything, and one solution that worked for me was turning off my Cloudflare WARP. If you have any VPN connected, turn it off.