How to reinstall Terraria on Steam

Solution 1:

You need to verify file integrity, which will automatically re-download missing or edited files.
Here's how you do it:

1. Right click on Terraria in your library and go to Properties

2. Now go to Local Files tab and click on Verify File Integrity

3. Wait until it's done verifying and after it's done, your game should work.

If this method doesn't work, you have to Right click on Terraria in Library and click on Delete Local Content, which will uninstall the game. For extra measure you could delete the whole Terraria folder (your worlds and characters are saved in a different folder) and then just install it again like you usually would.