PROBLEM: You have an Activity that you want to delete from the system, but can't because you're getting the message "This Activity is currently in use and cannot be removed. All occurrences of this activity must be changed or deleted before removing."
SOLUTION: From your CMS Membership System, click Process | Remove Activities (be sure you have a current backup before beginning this process).
Click the Activities button and select the Activity codes you want to clear from the Members in your database. Click OK.
Click the Activity Status button and click the Add All button in the middle. If you want to remove all traces of an Activity Code, select All Activity Status Codes.
This will remove this code from the people who had it assigned to them.
Next, click Options | Define Codes | Activities. Highlight the code you want to delete and click the Delete button on the right side of the screen. The system will now allow you to delete the code.