CloudMigrator returns the following error when migrating to OneDrive.
Unable to locate user properties. Is the user provisioned in SharePoint
This error occurs when an account exists in Office 365, but a OneDrive site has not yet been provisioned. Sites can be provisioned for the user by them signing in to OneDrive, or for all users by following this guide.
When you perform this provisioning, especially using Powershell, there is going to be a propagation delay. The delay cannot be estimated, unfortunately, as it depends, not only on the number of users but also other factors.