Could not establish connection. Receiving end does not exist" Browser automation stopped working

[Eduard_Dinges]

OpenRPA version: 1.4.57
OpenFlow version: Using app.openiap.io
Error message: Could not establish connection. Receiving end does not exist

Hi everyone,

I’ve been using OpenRPA with browser automation (NM Get Element, etc.) successfully on the same Windows 11 machine. However, since yesterday evening, all workflows using the browser connector fail with:

“Could not establish connection. Receiving end does not exist.”

The exact same workflows worked fine just a few hours before.
No system changes or updates were made in between.

Symptoms

• The error appears immediately when I run an activity like NM Get Element

• The OpenRPA logs show regular “Sending getconnections / Received reply” entries, and some tab update messages from the Chrome hook, but no actual responses or connection handshakes from the browser extension (no “connected” or “received” messages appear). Here are some Log-Entries from opening the selector and picker in nm.getElement:

  • [14:56:05.072][Error] “Could not establish connection. Receiving end does not exist.”
    [14:56:05.072][Debug] init selector model, with 0 root elements
    [14:56:10.107][Debug] Windows.Recording::OnMouseUp::begin
    [14:56:10.110][Selector] windowsselector::begin
    [14:56:10.142][Selector] windowsselector::create pathToRoot::end 00:00.033
    [14:56:10.151][Selector] windowsselector::create traverse_selector_both_ways::begin 00:00.042
    [14:56:10.163][SelectorVerbose] matches::FindAllChildren.isDesktop(True)::begin
    [14:56:10.316][Error] System.Runtime.InteropServices.COMException (0x80040201): Ein Ereignis konnte keinen Abonnenten aufrufen. (Exception from HRESULT: 0x80040201)
    [14:56:10.364][Verbose] [nmhook][resc][chrome]tabupdated for tab 1005661473 - 9910

• The Chrome Service Worker console shows every time I open the selector in NM.GetElement:
  ”Could not establish connection. Receiving end does not exist” as warning and as error:

  

• The process OpenRPA.NativeMessagingHost.exe runs correctly in the background and responds when launched manually.

• The Chrome manifest is correct: MessagingHost path and extention id are correct.

• The registry entry exists under HKCU\Software\Google\Chrome\NativeMessagingHosts\com.openrpa.msg
  (nothing under HKLM, which seems normal for a per-user installation).

What I’ve tried

• Restarted OpenRPA, Chrome, Edge, and Firefox (Per taskkill /F).

• Reinstalled the Chrome extension and OpenRPA (both “for all users” and “per user”).

• Deleted and recreated the OpenRPA settings.json.

• Verified that the Named Pipes are created:
  2_openrpa_nativebridge_chrome
  2_openrpa_nativebridge_chrome_1

• Disabled all other extensions and ensured full permissions are granted.

• Tested with different Chrome profiles.

• No antivirus or policies are blocking communication (Windows Defender checked).

• Running everything in the same user session.

• NativeMessagingHost returns valid “ping” responses when called manually.

Additional observation

• The green overlay used by the selector is broken — instead of highlighting the selected element, it only shows a small green cube in the top-left corner of the screen.

• The selector cannot highlight or pick elements on any page.

• The error occurs even on simple pages like example.com.

• This might indicate a coordinate or window handle issue, but even with 100% scaling and a single monitor setup, the same problem persists.

Current status

• Native messaging seems to initialize correctly, but OpenRPA never receives a response from the browser side (“receiving end does not exist”).

• The issue reappears even after full reinstall and affects all browsers.

• It looks like the OpenRPA client fails to attach the active Chrome tab, even though the bridge process and pipes are alive.

Question

Has anyone seen this recently or knows what could cause the extension connection to suddenly stop working, even though all manifests, registry entries, and pipes are correct?
Could this be related to a Chrome update or something breaking the Native Messaging handshake?

Any guidance would be appreciated. I can share full debug logs if helpful.

[Allan_Zimmermann]

I agree, this sounds like Chrome and OpenRPA not communicating together. I’ve seen this a lot during development, since every time you re-install the Chrome extension in developer mode, there is a chance its ID changes and you need to update the trusted IDs inside manifest.json.

But the Chrome extension has not been updated in over 2-3 years, so that is not the issue. Another way this can happen is if OpenRPA.NativeMessagingHost.exe is not running or working. Again, in the source code, this has not been updated in over 4 years, but maybe something on your system is blocking this from running?

• Open Task Manager and KILL any instance of Chrome and “OpenRPA.NativeMessagingHost.exe.”
• Open Chrome,
• go to ANY URL,
• make sure “OpenRPA.NativeMessagingHost.exe” starts.

If not, you need to figure out what is blocking OpenRPA.NativeMessagingHost.exe from starting.

[Eduard_Dinges]

Hello Allan.

Thank you for your reply. I agree with you that anything must have changed on my machine or the page otherwise the automation would still function.

OpenRPA.NativeMessagingHost.exe is running as it should and Verbose registers now (after reinstalling chrome and openrpa aigan) every action I do on the browser - but for an google-form (The subject of this post) Debug and Verbose only logging Tab selection at the very beginning but no further actions like mouse-clicks or keys. For this page the selector and picker does not work with the no connection message.

After some trys on this google form page it seems the whole connection becomes corrupt and the communication between extension and openrpa shuts down completely. Thats the issiue I described yesterday.,

Is there a known issiue with google-forms and do you have any idea what happend that my automation on this form stoppend working “overnight”?

And on which browser should I focus? I use chrome only because I know it best.

[Allan_Zimmermann]

Oh, I missed that part. Yeah, many, many years ago, I came across a site in Chinese that would cause OpenRPA.NativeMessagingHost.exe to go out of sync and be unable to continue after receiving what looked like a corrupted JSON message. I added better UTF-8 support and added some code to discard what could be a corrupted JSON message and try to “find” the next valid message so things can continue, but I would not claim that it is 100% bulletproof.

I have to be honest, I do not have time to debug/look into this at the moment, but if you CAN give me an example that can produce this issue, I’m happy to take a look when my calendar is less filled up.

[Eduard_Dinges]

Thank you Allan.

It is the form created by Marcelo Cruz for his Udemy-OpenRPA-Course ( Interresting udemy course about OpenRPA )

Link to form: forms.gle/hP1XKCkQdYykKinPA

My automation simply fills out the form by selecting the input fields using nm.getElement.

My machine is a plain current Windows11 with current and plain chrome version. no other Extentions installed.