@kellyaltom If you're on firmware 3.4.6 and can access DWC, you can just re-upload the 3.4.6 zip. It will create the firmware folder and put the files in the correct place. You can then delete all the firmware binaries out of the system folder.
Alternatively, you can use the M997 P parameter and tell RRF where the binary file you want to install is, eg:
M997 S1 P"0:/sys/DuetWiFiServer.bin"Ian