Insufficient SD storage space error! My SD (memory) card has about 14 GB of free storage space but when I try to open documents saved in my SD card, it says that there isn't sufficient space to open them. 

What could be the cause of this and what can I do to fix it? I am using a Samsung Galaxy S4 mini.
Try clearing data of the apps you dont need. It's probably your internal storage that's used up. You can even clear the cache of the apps in Settings>storage..