This error occurs due to a conflict in the membership record itself inside of The Raiser's Edge when processing a membership transaction. The Start Date of the membership transaction is actually less than the Renewal Date set on the membership record. As such, the transaction will not process unless the date either equals or is greater than the Renewal Date. To resolve the error, perform the following: 
  1. Log into The Raiser's Edge
  2. Click on the NetCommunity plug in 
  3. Select Memberships
  4. In the transaction grid, click Manage Memberships
  5. Make sure the Renewed On date is later than the Last Activity Date 
    User-added image
  6. Click OK
  7. Proceed to process membership transaction