When you create a file or a folder, do you check that the full path is not too long?! Make sure that you handle the PathTooLongException:
Try to exceed the maximim lenght on Windows, and you'll get this error:
Destination Path Too Long
Here are some limits in Windows APIs that you should know about:
#define MAX_PATH 260 // Maximum length of full path
#define MAX_DIR 256 // Maximum length of path component
#define MAX_FNAME 256 // Maximum length of file name component
#define MAX_EXT 256 // Maximum length of extension component