Why can’t I add more users?

Almost certainly because there are no more user slots available to allocate to a user.

If you are the system administrator, go to the portal at maestrolive.com and log in, then go to “change plan” and increase the number of user slots available and save.

You will now be able to add additional users.

Remember, you do NOT get charged for slots allocated to your instance, you are only charged for the slots that have been assigned to actual users.