Update: Issue should now be resolved. Please try migrating again!

We are aware of some users having issues completing the account migration from Mojang accounts to Microsoft accounts. During the flow, users are prompted with:

Clicking restart and migrating again will result in the same issue. The problem is caused by the Microsoft account payload (perhaps your Gamertag?) having special characters which we are incorrectly decoding. We are working on solving this problem, there is no workaround. Please be patient while we fix the problem. You can monitor when the issue is solved by clicking "Start watching this issue" to the right.