I´ve changed the language inGame from German -> English. After that, i´ve got the following error:

InvalidCastException: Cannot cast from source type to destination type.
at ForestBrush.GUI.BrushEditSection.LocaleChanged () [0x00000] in <filename unknown>:0
at ForestBrush.GUI.ForestBrushPanel.ForestBrushPanel_eventLocaleChanged () [0x00000] in <filename unknown>:0
at (wrapper delegate-invoke) ColossalFramework.PlatformServices.PlatformService/SteamControllerInitHandler:invoke_void__this__ ()
at (wrapper delegate-invoke) ColossalFramework.PlatformServices.PlatformService/SteamControllerInitHandler:invoke_void__this__ ()
at ColossalFramework.Globalization.LocaleManager.LoadLocale (System.String codeString) [0x00000] in <filename unknown>:0
UnityEngine.DebugLogHandler:Internal_LogException(Exception, Object)
UnityEngine.DebugLogHandler:LogException(Exception, Object)
UnityEngine.Logger:LogException(Exception, Object)
UnityEngine.Debug:LogException(Exception)
ColossalFramework.Globalization.LocaleManager:LoadLocale(String)
ColossalFramework.Globalization.LocaleManager:LoadLocaleByIndex(Int32)
<ChangeLanguage>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)