Empty folders can be clicked multiple times

[rickyManalo]

This makes the returned path null because the path of the empty folder gets concatenated to the return e.g. /storage/usbotg/usbotg I think. You should check whether a path can be accessed and remove or disable it from the list if it can't be.

[kashifo]

I agree, thanks for pointing it out @rickyManalo

[rickyManalo]

No problem. I recently learned about getExternalFilesDirs(), I think you could use that.