Why is my Alcatel Onetouch Pixi 9022X Tablet can't install apps

My tablet can't install apps but it has a lot of space. I inserted a SD Card that is 14 GB and set it on to default storage, I cleared all cache and the miscellenious files. I tried downloading an app but the tablet said that I need to free up space. I am frustrated about this. When I cleared everything I reset it then I tried downloading an app again but it keeps showing that I need to free up space. What am I supposed to do now?