System.Management.Automation.RemoteException occurred while making the powerhshell script to get lync users

Question

I have following c# code that will call a PowerShell script to get Lync users.

But the line below throws an exception:

powerShellInstance.EndInvoke(result); 

Exception:

[2018-11-21 12:12:10] - [ERROR] – System.Management.Automation.RemoteException: Value cannot be null. Parameter name: source at System.Management.Automation.Runspaces.AsyncResult.EndInvoke() at System.Management.Automation.PowerShell.EndInvoke(IAsyncResult asyncResult) at O365Management.PowershellWrapper.RunPowerShellScript(String userName, String plainPassword, PowerShellScriptType powerShellScriptType, String groupId) at O365Management.PowershellWrapper.GetLyncUsers(String userName, String plainPassword)

Any suggestion?

System.Management.Automation.RemoteException: 
Value cannot be null. 
Parameter name: source at System.Management.Automation.Runspaces.AsyncResult.EndInvoke()
at System.Management.Automation.PowerShell.EndInvoke(IAsyncResult asyncResult)


using (PowerShellProcessInstance instance = new PowerShellProcessInstance(new Version(4, 0), null, null, false))
        {
            using (var runspace =
                RunspaceFactory.CreateOutOfProcessRunspace(new TypeTable(new string[0]), instance))
            {
                runspace.Open();
                using (PowerShell powerShellInstance = PowerShell.Create())
                {
                    powerShellInstance.Runspace = runspace;

                    var filePath =
                        "c:\\GetLyncUsers.ps1"; // this script has a method, which call method of includeScript.ps1
                    powerShellInstance.Commands.AddScript(File.ReadAllText(filePath));

                    var includeScript = "c:\\includeScript.ps1";
                    powerShellInstance.AddParameters(new List<string>
                    {
                        userName,
                        plainPassword,
                        includeScript
                    });


                    PSDataCollection<PSObject> psOutput = new PSDataCollection<PSObject>();
                    IAsyncResult result = powerShellInstance.BeginInvoke<PSObject, PSObject>(null, psOutput);

                    int allowedIteration = (int)TimeSpan.FromMinutes(20).TotalSeconds / 5;
                    var noOfIteration = 0;
                    do
                    {
                        noOfIteration++;
                        Thread.Sleep(TimeSpan.FromSeconds(5));
                    } while (noOfIteration <= allowedIteration && !result.IsCompleted);

                    if (!result.IsCompleted)
                    {
                        throw new Exception(string.Format("Timed out. Killing powershell instance... Username: {0}",
                            userName));
                    }

                    powerShellInstance.EndInvoke(result);

                    return psOutput;
                }
            }
        }