Have you tried verifying integrity of your game files? To do this, open Steam and go to your Library. Right click on Terraria from the drop-down menu, and go to Properties. When you get to a little window, select Local Files tab and click Verify Integrity of Game Files. As soon as verification of integrity begins, you need to be patient. It's been a while since I've used the feature but I presume that a precentage bar will pop up and results will come up at the end, detecting issues. I hope this helps.