@dc42 said in fatal error: MessageFormats.h:

I think you are using an old version of project DuetWiFiSocketServer. Use the dev branch of that project.

It worked, I used the master branch, and when I selected DEV it compiled. There are 2 errors, but as I understand it, this is no longer a problem, since compilation of this file is not necessary.

@dc42 Hello, in this instruction
https://github.com/Duet3D/RepRapFirmware/wiki/Building-RepRapFirmware#instructions-for-building-under-windows
It is said that for the Duet 3 MB6HC payment you do not need to add DuetWiFiSocketServer.
Following your advice, I added DuetWiFiSocketServer to the space. The result is this. I am attaching photos of errors and environment settings.

Hello everyone, I am compiling RepRapFirmware version 3.4. For the Duet 3 Mainboard 6HC, once everything worked, but I changed the computer and now this error comes out. Please tell me how to fix this.
Thank you very much!!!