I have a method you could try:
Go to:
C:\Users\UserName\Documents\My Games\Terraria\Players
And find the corrupted character file, for example: Terrarian.plr
Back up the character file, just in case, then delete it
Then find the .plr.bak file of your corrupted character, for example: Terrarian.plr.bak
And rename it so the extension is just .plr, for example: Terrarian.plr.bak ---> Terrarian.plr
That should fix the character.
For the world, it's the same process
Go to:
C:\Users\UserName\Documents\My Games\Terraria\Worlds
And find the corrupted world file, for example: World.wld
Back up the world file, just in case, then delete it
Then find the .wld.bak file of your corrupted world, for example: World.wld.bak
And rename it so the extension is just .wld, for example: Terrarian.wld.bak ---> Terrarian.wld
And that should fix the world.
That's all I can think of for fixing corrupted Terraria files, I'm not too sure if it will work, but give it a try and backup any files you delete.