When you purchase a clone duet wifi it comes with either ver 1 or 2 os. This needs to be updated to at least 3.3 and the process is a real stressful operation.  I have had great success with alot of configurations using the duet wifi but ran into problems with 3.4 and this caused some real grief with a ne build. I will try to provide the instructions and files here

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• Users of RepRapFirmware 2.x cannot upgrade directly to this release because the binaries for the Duet 2 series are too large for the Duet 2 IAP programs. So you must upgrade to RepRapFirmware 3.0 first, then you can upgrade immediately to version 3.1.1. Alternatively, you can use Bossa over USB to upgrade directly to RepRapFirmware 3.1.1 but in this case you will need to upload DWC 3.1.1 and the appropriate IAP file separately.