SdFat-errorCode 0X50, 0X0

Hi people!

im using the last SdFat’s library version from greiman. Testing the program example bench i got an error code:

12:01:11.605 -> Type any character to start
12:01:14.390 -> chipSelect: 5
12:01:14.390 -> FreeStack: 0
12:01:14.390 -> Can't access SD card. Do not reformat.
12:01:14.390 -> SD errorCode: 0X50,0X0

Do you have any idea what does it means??

Infos: Board:NODE-ESP from Franzis connected with pc through usb.

SD Card: 4 GB intenso microSDHC class 4