Error - This project rate type is referenced as the default...
When deleting a rate type row from the project editor rates tab you may see the error message: This project rate type is referenced as the default project rate type or an allowed project rate type for one or more task types. Please remove all references before deleting.
Solution 1
A task type currently has this rate type assigned. Go to the task types tab and remove the rate type as an option in both the Default Rate Type and Allowed Rate Types columns.
Solution 2
The engagement type has this rate type as a default. On the Task Types tab of the engagement type editor you will need to remove the rate type as an option in both the Default Rate Type and Allowed Rate Types columns.