What is the problem?
My printer returns a file list when I send M20 and responds with OK on M21. However the GUI does not display any files on the SD card, nor can I upload or initialize the SD card.
What did you already try to solve it?
I've searched google and the forums as well as he FAQ. I found a somewhat similar issue with an improper response from M20, Marlin responds with echo:SD card ok, but my printer just responds with OK. I'm going to try and write a script/plugin to change that and see if it works
Logs (octoprint.log, serial.log or output on terminal tab, browser error console ...)
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ...)
Printer: Monoprice Delta Pro Lerdge X Mainboard running Lerdge firmware. Octoprint 1.3.1/octopi 0.15.1
[...]
Send: M21
Recv: ok
[...]