This points directly to driver issues. Open your Windows Device Manager and confirm that your phone shows up under Ports (COM & LPT) as an SPD/Spreadtrum COM port. If a yellow exclamation mark is visible, manually reinstall the Spreadtrum drivers.
This update added comprehensive support for the following devices: A51 lite, A71, C341, C570 G50, G60, M8L Usage and Requirements Hardware Requirement: nck dongle spreadtrum module 2.1.4 download
Which specific are you attempting to connect? Is your PC running a 64-bit or 32-bit version of Windows? This points directly to driver issues