Unable to login to Minecraft Launcher after migrating account :/

That's normal, you can't access the old Mojang account after the migration, you need to use the email you used to migrate the Mojang account to, in the launcher you need to select Minecraft Java and then Microsoft login and then use the email you use during the migration process

I want to log into my old username though. This logs me in as my Xbox Live Gamertag, not my migrated Mojang username which I've had since the the java edition was in beta. If I click the username in the top-left corner of the launcher to select my old username, it makes me sign in again and will not accept my Microsoft password so the problem doesn't end for me.

Thank you! What a terrible user interface. Glad I found this thread.

Thank you so much. What a relief.

Hello, how are you? My name is Mateus. I'm an Independent Advisor and I'll be glad to help you today.

First, welcome to the Xbox community. I'm sorry you're having this problem.

There is an important step where Microsoft and Mojang do not make it clear to everyone, please try to do the following:

On the Launcher login page, you must click the button to return to the accounts page. But then, don't click on your existing account that you want to log in or you'll simply fall back into the same cycle of problems that won't allow you to log in.

You need to add a new account. It's counterintuitive because you're not actually setting up a new account.

But after clicking to add a new account, you can choose to sign in with your Microsoft account in Launcher. After doing this, it will automatically use the Microsoft account to log in to Launcher.

*Please let us know if this works.