This article provides information to keep in mind when you cannot log in to your application account.
As of now, when you set up a user, you need a username, password, and an email address, as those are mandatory fields. Those users we set up initially and did not need an email address as mandatory at that stage were all kicked out. The issue here is that users who did not have their email address entered will not be able to reset the password, which means they can only access the application through the Request Access or Guest Access groups.
If clients have access to their original account, they will have to update their email address under Settings or add account request access in the application so you can assign the users to the appropriate groups. Additionally, you can add a custom form feature into the account request access where users can enter their details, which will determine the groups where the client belongs.