>The only thing I can think of is
>
>Changed
>(1) CallingConvention.StdCall
>(2) Use IntPtr for the dll return value, then convert IntPtr to string
>
>

> //declare string Invoke1 in (addbs(justpath(.cProgramPath)) + "ww_local.dll") as ww_localInvoke string cInvokeString
>
>        [DllImport(@"C:\Program Files (x86)\Siriusware\Pool\ww_local.dll", 
>            ExactSpelling = false, 
>            CallingConvention = CallingConvention.StdCall, 
>            CharSet = CharSet.Auto)]
>        static extern IntPtr Invoke1([MarshalAs(UnmanagedType.LPTStr)] String str);
>
>
>

>


>then
>

>string translate  = Marshal.PtrToStringAuto(Invoke1(invoke));
>
>return translate ;
>

Thanks a lot, I'll try that. I still think the issue is inside the newer version of that C++ dll, so I may need help from our C++ developers to find out. But I'll try your suggestion with both new and old dll.