Recuva error message

Received the following error message - volume for file externally altered.

After scan, it shows the correct number of deleted picture files but cannot recover. Any suggestions? Did the deep scan also.

Is the drive you are trying to recover to NTFS?

Do you have any backup or antivirus software running that could be interfering?

Are you attempting to recover to a drive that is also the drive the deleted file is on?