chan file system Long File Name Issue

I have a BeagleBoneBlack board. I have ported the chan file system (last version 2019)for the sd card of this board and it works fine. I can read and write files to/from the SD card. but there is a problem. when I set FF_USE_LFN macro to 1, f_open function failed and return value 13(no file system). I would appreciate for any kind of help.