If the web interface files are missing (which sounds likely from the error message) you will need to manually copy them from your PC.
nvm, looks like it;s working now.
The commands were to check what duet and firmware you had, and see if the SD card was working.
@zshoe said in Your Duet rejected the HTTP request:
SD card 0 detected, interface speed: 20.0MBytes
slot 0 detected and working.
@zshoe said in Your Duet rejected the HTTP request:
HTTP is enabled on port 80<LF>FTP is disabled<LF>TELNET is disabled<LF>ok<LF>
These are responses from executing your config.g.