General problems - Multiplayer problems + Game crashes on startup?
1. Turn the firewall off.
2. Try running the game in compatability mode. Go to "*Drive*:\Steam\steamapps\common\Terraria" right click choose properties. Then open the compatibility tab and change the settings.
3. Start the game.
.NET Framework Problems - Game crashes while playing/starting a server?
*Always make sure your game is not running, while you are doing this*
1. Close the game, deinstall XNA Framework Redistributable 4.0 and restart the game. If that won't work do step 2.
2. Go to "*Drive*:\Steam\steamapps\common\Terraria"
3. There are a few setups.
4. Run xnafx40_redist.
5. Run a dotNET Setup (depending whether you got 32- or 64-bit)
6. If that won't work do the next step.
7. Download the latest .NET Framework (4.5.2)
8. If that won't work reinstall Terraria.
How do I reinstall Terraria?
1. Deinstall Terraria on Steam, close Steam.
2. Go to "*Drive*:\Steam\steamapps\common" and delete the Terraria folder, if there is one.
3. Search with the explorer for remaining Terraria files, delete them.
4. Delete any files, which are interlinked with older Terraria versions, those might cause problems.
5. That includes deleting the files in "C:\Users\home\Documents\My Games\Terraria"
4. Restart your PC
5. Reinstall Terraria on Steam.