I have a Galaxy Tab 4 tablet. I am getting unfortunately X has stopped messages. How can I fix this?

[AC Question]

I have a galaxy tab 4 tablet. I am getting "unfortunately X has stopped" messages.

I have a galaxy tab 4 tablet. I am getting "unfortunately X has stopped" messages. It also freezes and shuts down on it's own. I cleared cache, took it back to factory, and downloaded Avast. I still cant get it to work. Any ideas??