Can't login to Minecraft with Microsoft account 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

Hi Uso. My name is Kyle and I'm an independent advisor.

Once a Minecraft account is migrated to a Microsoft account, it is permanently associated with that account. Unfortunately, you can't change this after migrating.

To clarify, you are having issues accessing Minecraft on the account you migrated it to?

Hello intansemc2,

Thank you for contacting the Xbox Support forums. I understand that you attempted the solutions provided in the linked forum post. Please note that solutions provided in the past may not be as accurate. It is suggested to contact Mojang directly regarding your personalized error you are receiving at Mojang Support - Contact Us since there may be specifics that aren't related to other users.

Additionally, please review Microsoft Account Migration Issues and FAQ / Minecraft: Java Edition Account Migration FAQ.

Thank you,

-Tali

Thank you for your Replay.

I tried to log into minecraft.net , it won't work because my minecraft i migrated to Microsoft. I can't login the Microsoft account is gone. Can Microsoft redeem my account?

The Minecraft account is from 2009, so its quite Import to me.

ok, but the issue is not your migration to Microsoft 365, this is because you migrated your Minecraft account, to a Microsoft account, and the error on the first screenshot is because you are trying to use the Mojang login still instead of the Microsoft login option at the top of that box