This happens because SP Flash Tool v6 is stricter. It checks the firmware for a valid scatter file and often checks for an accompanying XML structure to verify the DA (Download Agent) handshake.
If your ROM folder contains a file named scatter.txt and Sp Flash Tool V6 Xml File Download
However, modern MediaTek chipsets (such as Helio G series and Dimensity series) and updated security protocols required a more robust flashing environment. Enter . This happens because SP Flash Tool v6 is stricter