Argument 'BrowserInstance' must be 'Web browser instance'

[Dapta]

Hi

I have an issue where PAD at random gives me this error: Argument 'BrowserInstance' must be 'Web browser instance'

It can be both after either attaching to or starting a new browser.

But for this specific issue, it's just when I open the Chrome browser, navigate to a website and then I want PAD to click a button - and it's just about 50/50 whether I get this issue or not at this point.

PAD is executing unattended on a VM, and I have been wondering if it can be caused by a lack of resources? Is this a common error?

Does anybody know why this happens at random and what I can do to bulletproof this?

[MichaelAnnis]

Set up an on error action to reattach to the browser if an error occurs. 

[Dapta]

Hi @MichaelAnnis 

Thanks for your comment. I've tried that, and it usually bugs out as well, sadly.

It's hard to say, but maybe that solutions helps the error-rate up a bit from 50/50 to 40/60. None of my fail-safes has been bulletproof, as of now I'm having it close the browser, open a new instance and try the script again (which still fails).

I was hoping that there was something I've overseen in PAD - do you experience the same error commonly?

[RituT]

Hi, I had the similar issue while launching the New chrome browser instance and that got resolved after I have uninstalled and installed back the Microsoft power desktop extension. See if that works for you as well.

[Jimbotron3000]

Did you ever find a solution that works? This is happening to me constantly. Sometimes it hangs after opening the browser. With error handling set to continue on error after timeout, I then get the 'BrowserInstance must be Web browser instance' error.

[ryule]

Yeah I get this with IE and the Automation browser on my VM.....works just fine on my laptop....

[CParsons09]

I'm also facing this issue now that we are testing unattended automation. Re-installing the MS extension did not solve the issue.

[ryule]

My Edge browser has started doing this randomly.....

[ApexOrigin]

I have starting having some reliability issues recently with browser actions.  I am suspecting it has something to do with an update Microsoft made recently to the browser extensions.

In my case, I added wait statements, and the processes are more reliable now. These are processes that have been running on WinAutomation for years without any issue and without wait statements, and then all of sudden, issues. It's the same problem with PAD, so that's why I suspect a change to the browser extensions software.

[ryule]

Frustrating! So you are adding the wait statements before the action directly after starting the browser? I think I have some on most, but maybe I need to extend them.

[ApexOrigin]

I put them between all the code lines where the problem exists.

[samwhitt]

I had this issue, but only on a chrome window that always opened as a pop up. 

The attach to running instance wouldn't recognise it in the drop downs, so i installed the following web extension and it started to recognise it more consistently / without having to do anything more hacky. 

https://chrome.google.com/webstore/detail/open-link-in-same-tab-pop/jmphljmgnagblkombahigniilhnbadca

[zulfadlizabri]

The solution is to use Edge browser instead Chrome browser. I have similar error before and it works fine after I made this change.

I created a support ticket to Microsoft support team and they claimed that PAD is requesting you to change to MS Edge, which it will give an output variable as 'Web Browser Instance'.

Please mark this as solution if this step works for you. Thanks.

[ryule]

That is absolutely not true, and if it is, Microsoft needs to put out a much larger statement.

[Anonymous]

Hi All,

You can try using Launch New Chrome and set it's "On Error" property to "continue flow run", and then use wait for window action to check if window is open with the expected title & class. 

> if it is open, then check if %browser% variable is empty or not. if it is empty, attach to chrome browser, either by title or URL.

> %browser% variable is not empty, that means %browser% variable is initialized by Browser Instance.

> If window is not open, then you can try launching the browser again, you also try using the Terminate process action, just in case process itself is giving some issue.

Regards,

Inzmam

[EnochStrok]

Thank you! This resolved it! Simple solution!

To re-attach select Browser automation > Launch new Microsoft Edge

Launch Mode: Attch to running instance

Variables produced: **USE THE SAME ONE AS BEFORE**

[miguelE]

Hi, this is a late reply but this week my PAD was updated to the last version, 2.37.123. After the update all the processes stopped working. They all had the same problem 'BrowserInstance' must be 'Web browser instance'.

I found that setting up the action Launch new Microsoft Edge to retry 1 time after it failed (on the On Error tab) would make it work!
I did this on every process (I've 10) and they all started working.

I hope this helps!

[MattJimison]

@miguelE I had the same issue appear a few days ago and the retry on the Launch Browser action also fixed it - thanks!

[sfos83]

If anyone is still tracking this, I found that when I used multiple monitors at work it failed to recognise the browser...when I used a single monitor at home it had no such issue

Simple solution (for me anyway)!