Help! App store will not allow me to reinstall an app!!

[stupidmuggles1]

I tried searching on google, but no situation was the same as mine.

A few months ago, I deleted a game, and I want to re install it. It was a free app.
But everytime I hit install (because I already purchased it) it doesn't do anything.

Plus I already tried to erase apps just in case I didn't have enough memory.

Please help!!