Signing in to your Minecraft account is a complex task for the launchers, and there are many things that can go wrong. When things go wrong, Modrinth App will let you know by showing the “Unable to sign in to Minecraft” error window.

That window contains a generally helpful suggestion to check your account, as well as debugging information that should help you and our support agents to pinpoint the exact sign in issue that you are experiencing 📍

Modrinth App performs authorization in steps, and this article will list common issues for each step. For transparency, we'll try to give a general explanation of what the step does, and then describe each common issue for that step.

If you are a developer and would like to review the process, Modrinth App is completely open source, and the code related to the authorization process is publicly viewable.

To add your Minecraft accounts, use the “Steve button” in the upper left corner of the window. The sign in option in Settings is for your Modrinth account, which will allow you to follow and report projects in the future without leaving the app. We know this is confusing, and this is something we definitely plan on fixing in a future update.

When you have an unstable network connection, you may experience error sending request for url (<url>) errors. This means that Modrinth App tried to send a request to a specific URL, but the request didn't go through due to a network problem.

Please try again or check your internet connection. If the problem persists, make sure that your third-party antivirus software, firewall and hosts file allow for the connection to go through. Using a service like Cloudflare Warp can sometimes help as well.

Some steps may fail if you are signing with the wrong account. In the future we'll improve this aspect so you can know which account you are signing in with. For now, we recommend you checking out our support article on how to find the right Xbox account.

The first step of the authorization process is to authenticate your device with Xbox. During this step, Modrinth App generates and stores a key for your device. This key is used to sign all requests to Xbox.

The app then contacts Xbox services with the public version of this key in order to create the device token. This token is required to make further requests to Xbox services.

In the second step of the authorization process, Modrinth App contacts Xbox services to initiate the authentication session. If successful, Xbox services will provide Modrinth App with the address of the sign-in page, which the app will open in a separate browser view.

Modrinth has no control over the sign-in page and does not interact with it in any way other than waiting for the sign-in process to complete or be canceled. This page is provided by Microsoft, so it's not possible for “Modrinth to not accept your password”. If you're getting an invalid credentials error, it probably means that your credentials are indeed invalid.

If you are experiencing the error related to deserialization failure of JSON due to EOF at line 1, column 0, this is likely a cause of the rejected authentication request. This error means that the Xbox responded with nothing when the app expected a specific response.

This error is caused by the time on your device being out of sync. Time is relevant here because, as mentioned above, all requests to Xbox services are signed with your device key, and the signature must include the current time.

In the future, Modrinth App will automatically correct the time based on the network time, but in the meantime, you can start living in the now by automatically syncing your clocks.

In this step, Modrinth App contacts Microsoft services in order to retrieve the authentication token after you've signed in using the form in the browser window.

In this step, Modrinth App contacts Xbox services in order to authorize access to your Xbox account using the token provided in the previous step.

Similar to SisuAuthenticate, the sign in process may fail on this step due to your computer time being out of sync. See above on how to adjust your time to resolve this.

In this step, Modrinth App contacts Xbox services to request access to Minecraft services.

If you are receiving a deserialization error related to the missing IssueInstant field, it may be due to one of the following reasons.

You might be signing in with the wrong account that doesn't have an Xbox account associated with it. See the above section about the wrong accounts to make sure that you are signing in with the correct account.

In countries like South Korea, your account must be considered an adult in order to play Minecraft. If you are a minor, your account will need to be added to a family group, in which case the regional playtime restrictions may apply. You can learn more about this in the Minecraft's support article.

In this step, Modrinth App contacts Minecraft services in order to sign in to your Minecraft account.

If you're getting a deserialization error due to a missing access_token field, it may be because you've tried to sign in too many times in a short period of time.

This is one of the final steps. During this step, Modrinth App contacts the Minecraft services to verify ownership of the game.

In reality, due to the unreliability of this API when it comes to playing Minecraft with PC Game Pass, Modrinth App only expects a specific response and does not actively verify the entitlements.

The final step. In this step, Modrinth App contacts the Minecraft services in order to retrieve your Minecraft profile.

If you receive a deserialization error in this step due to a missing name field, it could be for one of the following reasons.

The Xbox account that you signed in with does not have a Minecraft license and is not subscribed to PC Game Pass. See the above section about the wrong accounts for more information on how to verify that you are signing in with the correct account.

If you just purchased the game or subscribed to PC Game Pass, you will need to launch the game at least once using the official Minecraft Launcher in order to set up your Minecraft profile.

If you find this article confusing and have a hard time following it, an interactive support experience is available through our support bot. To start, just click the green chat button on the bottom right of your screen and choose 🚀 Modrinth App (launcher) and then 🔑 Can't sign in to Minecraft account.

Except for the cases not fully covered by this article or our interactive support experience, no support will be provided for sign in issues, and any incorrectly filed inquires related to sign in issues may be closed with or without a notice.