This message informs us that the Sign-up request was not generated from a new user sign-up on the website.  Instead, it was generated by the system because the Blackbaud NetCommunity account was previously linked to a Raiser's Edge record that was either deleted, or merged into another Raiser's Edge record. 

A sign-up request with this message can be processed normally. 

However, you should check with the Raiser's Edge team at your organization to determine why the original record was deleted/merged before determing how the user sign-up should be processed .  For example, if duplicate records were merged; you don't want to create a new constituent record for the sign-up.