I go to system -> user security -> Users-> Roles and try to remove the role from a user, but i only get an button telling me to "Cancel".
The user in question is member of the Master Role/Scope
How can I remove this Role/Scope from the user?
All users on the system must have at least one role and scope assigned to them.
If you have a Master role, then you must have the master scope - it is a requirement of the system.
You cannot leave a user without a Role and Scope, so removing the master role from the user, will automatically remove the Master scope, and this will leave the user without a scope.
To avoid this issue, make sure that the user has more than one role/scope assigned to them, before trying to remove the Master Role/Scope from the user