Troubleshooting intermittent error "Cannot communicate with the browser, please check the UiPath extension" while automating Chrome browser due to high resource utilization

How to troubleshoot intermittent "Cannot communicate with the browser, please check the UiPath extension" error that occurs while launching Chrome browser due to high resource utilization?

Issue Description: Error "Cannot communicate with the browser, please check the UiPath extension" occurs intermittently while launching browsers either using Open Browser or Use Application\Browser activity

Troubleshooting Steps:

This issue is usually observed in one of the following scenarios:

High system resource utilization

  • When the activity attempts to launch or load a browser\web page, it waits for a specific timeout period (default is 20 seconds with UI Automation activity version 22.10.x or lower and 60 seconds starting from 23.4.4 version)
  • If the browser fails to start within the specified time due to various factors especially like high resource utilization, the activity throws the aforementioned error message
  • To validate the resource utilization, refer to the Task manager's performance tab to find the CPU and RAM consumption during the automation execution. The consumption should be usually lesser than 80%


MV3 Extensions

  • Refer to this documentation of List of UiPath Extensions for Chrome to know if the extension is MV2 or MV3
  • For MV3 extensions, the browser loads the extension later, after the web pages have loaded
  • Machines that are really slow to actions being performed and also machine with lower specifications might fail with the above error

Resolution:

Increase the time out value (try 120 or greater) of the activity as instructed below.

Note: The following configuration is available starting from 23.4.4 or greater versions of UiPath.UIAutomation.Activities

For Classic - Open Browser activity: (project level setting)

  • In the Studio Project Settings, navigate to UI Automation Classic → Browser → Open browser timeout (seconds)

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For Modern - Use Application or Browser activity: (project level setting)

  • In the Studio Project Settings, navigate to UI Automation Modern → Application/Browser → Open browser timeout (seconds)

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Alternatively, the timeout value can also be configured through a Windows environment variable (machine level setting) as mentioned below. The following step would require admin access to make these changes.

Note: The following option is available with the following UiPath.UIAutomation.Activities versions:

  • 20.10.13 or greater in 20.10.x
  • 21.10.8 or greater in 21.10.x
  • 22.4.10 or greater in 22.4.x
  • 22.10.6 or greater in 22.10.x
  • 23.4.4 or greater versions


  1. Press Windows + R to open the Windows Run prompt
  2. Type in sysdm.cpl and click OK.
  3. Open the Advanced tab and click on the Environment Variables button in the System Properties window.
  4. Under the System-variables, enter the variable name as UIPATH_OPEN_BROWSER_TIMEOUT_SECONDS and value as 120 in the New User Variable prompt and click OK. Note: Try with an higher value if 120 does not help.

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For older versions of UiPath.UIAutomation.Activities or wherever the above options are not applicable, implement a retry logic activity that tries to capture the error and re-launch the webpage\browser using Retry Scope activity.

Additionally, reach out to the internal IT team to optimize resource consumption or consider increasing machine resources to enhance reliability when launching applications.