i have problems with the my games folder and thus can't login to terraria

This is the message I see when I try to start up terraria:
System.Threading.SynchronizationLockException: Object synchronization method was called from an unsynchronized block of code.
at Terraria.IO.Preferences.Save(Boolean createFile)
at Terraria.Main.SaveSettings()
at Terraria.Main.OpenSettings()
at Terraria.Main.ClientInitialize()
at Terraria.Main.Initialize()
at Microsoft.Xna.Framework.Game.RunGame(Boolean useBlockingRun)
at Terraria.Program.LaunchGame(String[]...

i have problems with the my games folder and thus can't login to terraria