I can't update the firmware of the MMU2S

[hartpa]

Description of the bug

I have connected the MMU to my computer via a USB cable. I'm trying to load the "prusa3d_fw_MMU3_3_0_0.hex" firmware. When select Upload printer firmware, I get an error message:

Flashing Original Prusa Multi Material 2 & 3 Upgrade (bootloader), looking for VID/PID 0x2c99/3 or 0x2c99/4 ... The Original Prusa Multi Material 2 & 3 Upgrade (bootloader) device was not found. Original Prusa Multi Material 2 & 3 Upgrade (bootloader) not found

Project file & How to reproduce

prusa3d_fw_3_13_0_MK3S_3_0_0_MMU2S.zip

Checklist of files included above

• [ ] Project file
• [ ] Screenshot

Version of PrusaSlicer

Version: 2.7.1+win64 Build: PrusaSlicer-2.7.1+win64-202312121425

Operating system

Windows 11 Home, version 23H2, build 22631.3007

Printer model

PRI-MK3-KIT-ORG-PEI, ORIGINAL PRUSA MK3/MK2 MULTI MATERIAL 2.0

[hartpa]

The same issue was on PrusaResearch forum.