Return of Reckoning

Hello,

The game is starting, but i have this :

Data.myp:
System.Exception: You need to stop application currently using the following file: data.myp
à MYPHandler.MYPHandler.WriteFileToArchive(FileInArchive archFile, MemoryStream MS)
à MYPHandler.MYPHandler.ReplaceFile(FileInArchive archFile ...