There might arise 2 cases when the scan is finished and you are about to save recovered files back to your computer.
Case 1: "Source and destination volume are same"
This message will prompt when the data recovered from a volume is being saved to the same volume. E.g: HDD was scanned for deleted files & the same HDD is being selectd as a location to save the recovered files. Hence, the message appeared.
To overcome this message, always choose a different volume to save the recovered files.
Case 2: "The destination you have chosen is on the same source drive as source"
This message only warns that the volume scanned for deleted files and another volume chosen to save recovered files lies on the same hard drive. You can simply click the "Proceed Anyway" button to ignore this message.
Important Tip: Always ensure an external device, which is larger than the source media to save your recovered data. In case you don't have any external media then choose a different volume to save recovered files.