Free download firmware for Coolpad E580 MediaTek MT6735. This firmware comes from a normal phone that is backed up. Update using the latest SP Flash Tool and unchecking the Preloader. If it fails or the PMT Changed message appears on the SP Flash Tool, check all partitions and select Firmware Upgrade.
Don't forget to backup all data on the device before flash. Read the descriptions in the table to anticipate the incorrect download of firmware that doesn't match your device model.