If you have access to create users or add users to a project. You may find that you can not save the user. In the most common case, the account has reached the user limit.
If you see the option to add a user and you have a field in all the field and no action occurs after clicking create. Your account may have reached the user limit. You should reach out to the primary admin or your Mediasilo account manager for a request to increase the limit.