If you have recently converted an Office 365 domain to federated then back from federated to standard, you can sometimes forget to convert the users of that domain back to standard as well. You might not even realize that users can remain federated even on a standard domain. All this really does is make it impossible to reset the user’s password through Office 365.
When a user is still federated and you try to reset their password through the admin portal it will not allow you to and you will get the error message – “Unable to reset this user’s password. Try again later”. This can happen when you use the -skipuserconverstion:$true flag attached to the convert-MSOLDomaintoStandard command. If you try to reset the password using powershell, you get the following error:
Once you know about this, the solution is rather simple. Start up powershell and sign in as you normally would – for information on how to get started with powershell, see this article. Then run the command:
Convert-MsolFederatedUser -userprincipalname email@example.com
Where firstname.lastname@example.org is replaced by the userprinciplename of the user you are converting. Once you run this command, it should give you a new temporary password for that user. Once you have this, you can proceed to reset the user’s password any normal number of ways, including signing into webmail as the user and going through the password reset procedure, or resetting it via powershell.