InternetExplorer COMException: System.Runtime.InteropServices.COMexception: The RPC server is unavailable


I'm very new to C# so please excuse me if it's a silly question.

I created a console application that uses the "InternetExplorer" from SHDocVw. This application goes to a website and performs some operations. It works just fine on my computer, but when I try to publish it I just can't to get it to work on my colleagues computers. These other computers don't have dotnet core installed.

So if I publish the app as framework-dependant I get a hostfxr.dll missing library error and it obviously doesn't work at all.

I thought I could fix this by publishing the app as self-dependant. This didn't help either. I always need to paste the "Interop.MSHTML.dll" and "Interop.SHDocVw.dll" manually. When I do, the app at least starts. Internet explorer shows up, the "Navigate" command works. But as soon as I try to hide the window, or try to work with elements in the page, it just crashes.

There are two types of errors I get:

  1. Unhandled Exception: System.Runtime.InteropServices.COMexception: The RPC server is unavailable. (Exception from HRESULT: 0x800706BA) at SHDocVw.IWebBrowser2.set_Visible(Boolean pBool) at MyWebApp.IEDriver.Visibility(Boolean isVisible) at MyWebApp.Program.Main(String[] args)

  2. Other times I get a very similar error, but it's even mentions my own user files, even when running on a different machine. Is that normal?

Unhandled exception. System.Runtime.InteropServices.COMException (0x800706BA): The RPC server is unavailable. (0x800706BA) at SHDocVw.InternetExplorerClass.get_ReadyState() at IEAutomation.IEDriver.WaitForComplete() in C:\Users\St3ve\source\repos\MyWebApp\MyWebApp\IEDriver.cs:line 552 at TestWeb.Program.Main(String[] args) in C:\Users\St3ve\source\repos\MyWebApp\MyWebApp\Program.cs:line 82

I tried to to google the errors, but can't get it work, I would be really grateful for any hints or help.

asked on Stack Overflow Feb 18, 2020 by St3ve • edited Feb 18, 2020 by Clint

1 Answer


The crux of this approach is to make sure we are accessing the right InternetExplorer object that is associated with our process

private InternetExplorer _IE; 

public Process m_Proc = Process.Start(@"C:\Program Files\Internet Explorer\iexplore.exe", "-nomerge");

public IEDriver()

    _IE = null;
    ShellWindows m_IEFoundBrowsers = new ShellWindows();
    foreach (InternetExplorer Browser in m_IEFoundBrowsers)
    if (Browser.HWND == (int)m_Proc.MainWindowHandle)
    _IE = Browser;

Then in your methods like WaitForCompleteNew(), Navigate(), etc where ever you attempt to access InternetExplorer's proprties or methods, you can use object _IE.

_IE.Visible = false;
document = ((HTMLDocument)_IE.Document)
answered on Stack Overflow Feb 18, 2020 by Clint • edited Feb 18, 2020 by St3ve

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