On PersistentStorage("SD") initialize gives me systemexception? someone can help me?

NETMF & Gadgeteer
1 
private static mStorage;

public void Initialize()
{
 mStorage = new PersistentStorage("SD") ;
}

why this gives me system error?

2

Many reasons!

Good power source?
Good SD card brand?
Formatted card?
Try different cards?

3

that won’t compile… missing static object type.