"Illegal characters in path" error opening service config file

Question

I am trying to read a section of a Windows service configuration file and extract a value (port number). Following code works fine on my local machine but not in any server I tested even though the service is installed in exact same folder structure.

On servers, I get "illegal character in path" error (I added a couple of try-catch to see where it dies and what the message was).

public static string GetCurrentTCPPort()
{
    string sTCPPort = "7899";
    string ServiceName = "IDC - Tcp Interface Service";
    using (ManagementObject wmiService = new ManagementObject("Win32_Service.Name='" + ServiceName + "'"))
    {
        try
        {
            wmiService.Get();
        }
        catch (Exception ex)
        {
            throw new Exception("Died in GetCurrentTCPPort - wmiService.Get()");
        }
        string ServiceExePath = wmiService["PathName"].ToString();
        System.Configuration.Configuration config;

        try
        {
            config = ConfigurationManager.OpenExeConfiguration(ServiceExePath); // FilePath = "C:\\IDC\\APP\\IDC - Tcp Interface Service\\IDC.Service.TcpInterface.exe.config"
            string[] saLiteningIPs = config.AppSettings.Settings["TcpServerListenIpAddrsAndPortNos"].Value.Split(',');    // "1.2.3.4:7899,1.2.3.5:7899"

            if (saLiteningIPs.Length > 0)
            {
                sTCPPort = saLiteningIPs[0].Split(':')[1];
            }
        }
        catch (Exception ex)
        {  // This exception is thrown

            string sExcep = string.Format("Died in GetCurrentTCPPort - OpenExeConfiguration(); ServiceExePath: {0}{1}Exception: {2}", ServiceExePath, Environment.NewLine, ex.Message);
            throw new Exception(sExcep);
        }
    }
    return sTCPPort;  
}

When I run it, I get:

Died in GetCurrentTCPPort - OpenExeConfiguration(); currentserviceExePath: "C:\IDC\APP\IDC - Tcp Interface Service\IDC.Service.TcpInterface.exe"
Exception: An error occurred loading a configuration file: Illegal characters in path.

Screen shot of config file location:

Update - With the fix

public static string GetCurrentTCPPort()
{
    string sTCPPort = "7899";
    string ServiceName = "IDC - Tcp Interface Service";
    using (ManagementObject wmiService = new ManagementObject("Win32_Service.Name='" + ServiceName + "'"))
    {
        try
        {
            wmiService.Get();
        }
        catch (Exception ex)
        {
            throw new Exception("Died in GetCurrentTCPPort - wmiService.Get()");
        }
        string ServiceExePath = wmiService["PathName"].ToString();

        // Added below two lines to fix the issue
        List<char> invalidPathChars = Path.GetInvalidPathChars().ToList();
        invalidPathChars.ForEach(c => ServiceExePath = ServiceExePath.Replace(c.ToString(), String.Empty));

        System.Configuration.Configuration config;

        try
        {
            config = ConfigurationManager.OpenExeConfiguration(ServiceExePath);
            string[] saLiteningIPs = config.AppSettings.Settings["TcpServerListenIpAddrsAndPortNos"].Value.Split(',');

            if (saLiteningIPs.Length > 0)
            {
                sTCPPort = saLiteningIPs[0].Split(':')[1];
            }
        }
        catch (Exception ex)
        {  // This exception is thrown

            string sExcep = string.Format("Died in GetCurrentTCPPort - OpenExeConfiguration(); ServiceExePath: {0}{1}Exception: {2}", ServiceExePath, Environment.NewLine, ex.Message);
            throw new Exception(sExcep);
        }
    }
    return sTCPPort;  
}

Answer 1

I am not sure why this happens when application is deployed to server and not when I run it locally, even though folder structure and files are exactly same on both; maybe there are invisible characters that are caught on the server but not locally.

Nonetheless, it seems the following modification fixed the issue, in case anyone else runs into this problem.

Right below the line getting the exe path, added these two lines:

string ServiceExePath = wmiService["PathName"].ToString();
List<char> invalidPathChars = Path.GetInvalidPathChars().ToList();
invalidPathChars.ForEach(c => ServiceExePath = ServiceExePath.Replace(c.ToString(), String.Empty));

I have also updated the the question.