Return of Reckoning

Error: System.UnauthorizedAccessException: Access to the path 'D:\Return of Reckoning\art.myp' is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share)
at WarZoneLib.MYP.OmppUfeT8vuhVZN8MH(Object , FileMode , FileAccess )
at WarZoneLib.MYP..ctor(String fileName, FileAccess access)
at WarZoneLib.MYPManager.Get(MythicPackage archive)
at RoRLauncher.Client.gGUhKmcY0MwYwiWiANN(MythicPackage archive)
at RoRLauncher.Client.Handle(PacketIn packet)
at RoRLauncher.Client.uVm3RMckDq5gW3822Li(Object )
at RoRLauncher.Client.OnReceive(PacketIn packet)
at RoRLauncher.Client.sQFFQNc4xaG4Xv8fcHj(Object )
at RoRLauncher.Client.tkeprHWAcH(Object )

this is the reading I get when trying to log in after putting all files on Read only.
After changing it back and turning read only off, it says unable to find something and reinstalling the game may fix this bug?

Any help would be great. Really keen to get back into this game