We are currently evaluating this issue and will update this article when we have more information.

This error message will occur when you attempt to delete a guest pass benefit from a membership program after selling that benefit to a constituent through a sales order.  In the meantime you can follow these steps to resolve the issue. To resolve this error message you must delete the guest passes that were sold to the constituent from the constituent's record. After that is completed you can then delete the guest pass benefit from the membership program's record.

Locate the Guest Pass on the Constituent's record
  1. Click Constituents > Constituent Search > Search for and Select the Constituent 
  2. Click on the Guest Passes tab 
  3. Click the arrow next to the Guest Pass > Click delete
Remove the Guest Pass from the Membership Program
  1. Click Memberships > Click on the name of the Membership
  2. Click on the Benefits tab
  3. Click the edit button
  4. Click on the Blank Space on the left next to the Benefit's name
  5. Press the Delete button on your keyboard
  6. Click Yes
  7. Click save