Unable to access memory card
Unable to access memory card only directories are shown .. no file is displaying in memory card
Files are not listing on Root folder of SD card only. Rest working fine.
Can you check this behaveour on android versiom < 22. Maybe this is due to processing runtime permissions?
You should handle runtime permissions in activity, from what you called Material File Picker like this
I will add this information to README
I am using the sample application listed here (https://github.com/nbsp-team/MaterialFilePicker/blob/master/app/src/main/java/com/dimorinny/sample/MainActivity.java#L38-L69) still unable to access the memory card.
It starts at /storage/emulated/0 and clicking on the back arrow goes to main activity

Still no one has solution for accessing SD card?
.withRootPath("/storage/")
Will open SD card and Internal storage