Firmware update not working on Code 25



I've tried uploading the firmware on my Marshall Code 25 using the Chrome, Opera and Edge latest browser versions on my Macbook pro 12.3 (Monterey) using a midi usb cable.

When doing the update the amp connects and allows me to click update... it shows the progress to 100% but then gives the error below:

"An error occurred. The update process was not completed. Please try restarting your computer/device, and then try the update process again."

I must have tried this a 100 times with no success.

Now when i resart my amp to play some tunes the display says "CHK USB" and the amp wont work.

This is all very frustrating and i hope someone can assist.

edited 27 Mar 2022 at 01:33 PM

Karl Benn

asked 27 Mar 2022 at 01:00 PM

Karl Benn
Answers: 2


Hi Karl,

Please try the below to see if this helps ,

 MIDI troubleshooting tips:

  • Make sure that there aren’t other apps running that could be using the MIDI drivers, for example a DAW or MIDI monitor.
  • Make sure that there aren’t other browser tabs open that could be accessing the MIDI ports.
  • Try to switch the amp on in bootloader mode, by holding down the PreFX, Mod and Rev and then turning the amp power on.
  • Try a different USB cable.
  • If has access to a Windows PC, try downloading the firmware updater app from the MyMarshall website.


Marshall Support


answered 28 Mar 2022 at 03:15 PM



i also faced same issue, will try the trubleashooting tips.  dickssportinggoods feedback survey ?

edited 20 Apr 2022 at 03:10 PM

jose sally

answered 16 Apr 2022 at 12:12 PM

jose sally
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