When adding a flat rate in Altru you may receive an error message that says: The selected group type is already associated with a rate scale.
This error message may appear in Altru when you're attempting to add a flat rate scale with a group type that is already used on another flat rate scale. When creating flat rate scales in Altru you must use a unique group type that is not used on any other flat rate scales, or leave the group type field blank
You can check the group types used on your flat rates by following these steps:
Click Tickets > Group Sales Setup
Click Flat rate pricing
The group type column will display all group types in use by other flat rate scales