Resolved FatalExecutionEngineError Occur after DllImport

[parker1107]

I have a Delphi DLL(x64) that provides a method to log in to the server.
I tried to add this method in a specific SDK. (COM Visible=true,select x64 for the platform)

Function LoginLic(sFD,sVD,sINI,sCh,sSD: string) : PWideChar; stdcall;
var sysServer,sysPort,sysLN,sysCN,sysIP,sysMac,sysDN,sysFN,sysFV,sysSN,
    sFile,sHost,sPort,sSN,
    sTempPath : string;
    myIni : TIniFile;

begin
   { example:
   [Connection]
   HostName = 192.168.1.187
   Port = 220
   }
   sHost := '127.0.0.1';
   sPort := '220';
   sSN   := 'SN109001';
   sTempPath := sINI;
   ForceDirectories(sTempPath);
   sFile     := sTempPath;
   if FileExists(sFile) then
   begin
      myIni := TIniFile.Create(sFile);
      sHost := myIni.ReadString('Connection', 'HostName', '127.0.0.1');
      sPort := myIni.ReadString('Connection', 'Port', '220');
      sSN   := myIni.ReadString('Connection', 'SerialNo', 'SN109001');
   end
   else
   begin
      myIni := TIniFile.Create(sFile);
      myIni.WriteString('Connection', 'HostName', '127.0.0.1');
      myIni.WriteString('Connection', 'Port', '220');
      myIni.WriteString('Connection', 'SerialNo', 'SN109001');
   end;

   sysServer := sHost;
   sysPort   := sPort;
   sysDN   := GetDomainName;
   sysLN   := GetLoginName;
   sysCN   := GetMyHostName;
   sysIP   := GetIP;
   sysMac  := GetMac;
   sysFN   := sFD;
   sysFV   := sVD;
   sysSN   := sSN;
   try
      Result := PWideChar(DoConnect(sysServer,sysPort,sysLN,sysCN,sysIP,sysMac,sysDN,sysFN,sysFV,sysSN,sCh,sSD));
   except
      Result := PWideChar('0;'+Result);
   end;
   Result := PWideChar(Result);

end;

public class EDABank
{
    [DllImport(nameof(EDABank), CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall)]
    [return: MarshalAs(UnmanagedType.LPTStr)]
    public static extern string LoginLic(string name, string version, string inipath, string checkDate, string subDate);
}

 string msg = EDABank.LoginLic(name, version, ini file path, "0", "");
 MessageBox.Show(msg);

I set a breakpoint at MessageBox.Show and get the message that I expected.

Then, throw the exception:
Managed Debugging Assistant 'FatalExecutionEngineError': 'The runtime has encountered a fatal error. The address of the error was at 0x0a283aad, on thread 0xd774. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.'


Is it possible to confirm what caused the problem to occur?

 

[jmcilhinney]

Please provide ALL the relevant details in the thread. The title should just be a summary of what is in your post(s) yet I see no mention of an actual error in your post. Please provide a FULL and CLEAR explanation, including exactly what you did and exactly what happened.

 

[Skydiver]

What happens if you comment out the contents of the entire Delphi procedure, and just have it return the string "Hello, World"? Do you get the same crash?

 

[parker1107]

What happens if you comment out the contents of the entire Delphi procedure, and just have it return the string "Hello, World"? Do you get the same crash?

Hi, Skydiver
I tried your suggestion this morning.
First, it just returned "Hello World!" in Delphi, it worked, and there was no error.
Then, I added ShowMessage after each function in Delphi DLL for confirmation errors.
The weird thing is that everything is working and FatalExecutionEngineError is gone.