[🐛 Bug]: driver.WindowHandles does not detect new tab opened by link or script in Selenium 4.26.0 (C#/.NET)

[shyampatadia]

Description

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🐞 Bug Report: driver.WindowHandles does not detect new tab opened by link or script in Selenium 4.26.0 (C#/.NET)

Summary:
In Selenium WebDriver version 4.26.0 for .NET (C#), the driver.WindowHandles property intermittently fails to detect new browser tabs opened via anchor links (target="_blank") or JavaScript triggers. This behavior was not observed in previous versions and leads to NoSuchWindowException errors when switching to a newly opened tab using known working methods.

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💻 Environment:

Component	Version
Selenium WebDriver	4.26.0
Language Binding	C# (.NET)
Browser	Google Chrome (latest)
ChromeDriver	Matches browser version
OS	Windows 10 / 11

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✅ Expected Behavior:

After clicking a link that opens a new tab (e.g., target="_blank"), driver.WindowHandles should contain both the original and new tab window handles. Calling SwitchTo().Window() with the correct handle should allow switching between them.

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❌ Actual Behavior:

driver.WindowHandles continues to return only one handle, even after a second tab is visibly opened. This causes tab-switching logic based on partial window title or handle to fail.

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Reproducible Code

Use the `driver.WindowHandles` method when 2 tabs are opened, on a browser, it returns me only one handle, and not 2.

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ℹ️ Last known working version: 4.26.0

[selenium-ci]

@shyampatadia, thank you for creating this issue. We will troubleshoot it as soon as we can.

Selenium Triage Team: remember to follow the Triage Guide

[shyampatadia]

Closing this issue since similar issue was created earlier!

Link to the Previous issue

[AlokB1993]

Hi @selenium-ci , @shyampatadia, @navin772 , I'm still seeing the same issue on Chrome 136.0.7097.0 , as comments are disabled there (Not allowing me even if i have created the bug) #15703. May i know what is the exact resolution we are working on or do I need to create another bug on any other platform.

[shyampatadia]

I dont think this issue is resolved yet, I closed the bug assuming that the issue wont be there for the chromdriver 136.0.7097.0, but when I actually tried it, the issue is still there, one of the engineer on chromedriver bug, mentioned that its resolved, but it has not been resolved, for now I am just using browserversion < 133.0

[navin772]

Hi @AlokB1993, @shyampatadia can you share reproducible code for which you are facing the errors?
I had a script that opens a PDF in a new tab which was giving errors in earlier versions of chrome (v134) but now works perfectly with v136 after the chromedriver fix.

[AlokB1993]

Hi @navin772 ,

In the code snippet, this method line no. 111 we are opening a new window and switching to that and before switching i have stored the parent window handle to scenario context. And in line number 120 from the code snippet i have the window handle of the parent page. after execution of line 119(Which closes the new window after clicking on add button) when i try to switch back to parent page, i get the exception No such window. Please find the attached screenshot.

[navin772]

@AlokB1993 I would need a minimal reproducible example (MRE) that I can run locally without the need of other dependent functions as in your code in order to find a resolution. Can you help me with that?
You can refer this for MRE.

[diemol]

@AlokB1993 that is not actionable at all. Screenshots give context but we need the actual code script to reproduce the issue.