Hi Simplify3D team,
Regarding the printing from SD card feature, there is an issue with Marlin firmware project: https://github.com/MarlinFirmware/Marlin/issues/6723
Because of the poor network connection quality (bluetooth), I strongly need the function work.
What I found was, when I calling "M20", marlin gives me the list of files in all CAPITAL file names, and I selected it from Simplify3D dialog, and
the problem is
sending "M23 $" command, the filename $ was ALL IN LOWER CASES, so marlin just saying open failed that file, which is not expected.
When I manually copied the file name from M20 result and pasted to M23, it works.
Please consider an option to not to convert the filename into lower case.