There are several usernames which are reserved for internal use by the Makerble application. Among these are the names edit and admin. For this reason, you will see a Warning Message saying Friendly is reserved if you try and name a user with one of those names or another reserved name.
Therefore the solution is to rename the user to an alternative name e.g. “z - not in use - 1”, “z - not in use - 2” etc.