RDP to User with Microsoft Account

It's pretty obvious really: a user creates an account for someone with "add a user" and uses a Microsoft Account email, only trouble is, the other user is only able to log in with remote access, but since there is no password stored for the account (there hasn't been a sync since the user hasn't been able logged in yet), that's not possible.

Only solutions I can think of are exchanging passwords and setting password from Computer Management (haven't tried, but the option isn't available from Control Panel, so not certain if that's possible either), but uncertain of the consequences of the latter (I'm aware of the consequences for a local account however, but how/would that affect sync, etc?).

Oh, and obviously there are third party remote access solutions one can use for the login...

It may have nothing to do with how the account was created.

Have you tried loosening the requirements set on the server-side (i.e. turn of network-level authentication requirement, etc.)?

For example, some of the previous versions of the RDP client can't do that type of authentication, and as it says "Allow connections only from computers running Remote Desktop with Network Level Authentication". So if the client isn't using it, it will disallow the connection.

Also ensure you've added the user to the Remote Desktop Users groups (I don't believe this is necessary if they're a member of Administrators group).