You need the firmware version V4.4.3 at a minimum to use with Chitubox 1.9.0 New firmware for ELEGOO MARS 2 PRO link: http://18.104.22.168/tutorial-download/?t=MARS_2_PRO_Firmware_F9.23 How to update firmware link: https://www.chitubox.com/en/article/support/howto/chitubox-pro/install-activate/how-to-update-your-printer-firmware I could not update my printer following the guidelines of Chitubox by inserting the USB and turn on the power for automatic update. I did it reversely. Turn on the printer, and then insert the USB. Open the file like you print a model. Click on the file name "update.TWP". It worked flawlessly.