[Bug] [Issue #409] Lost background heart beat when running command



After a few hours of running I am getting an error message

lost background heart beat when running command

The message comes at random points through the macros and is not associated with a specific step. In general the script simply opens up websites clicks a few links, deletes cookies and moves onto a new website.

Anyone have any ideas how to resolve this.



We have a few other reports of this issue, but we are still looking for a reliable way to recreate and fix this. Therefore, some question:

  • What kind of macro are you running (short or long macro? What does it do?)
  • How do you run it for hours? Are you using the LOOP button, or does the macro itself run for hours, e. g. with the Goto or while commands?



The macro is 750 lines long. It visits websites, pauses, deletes cookies and opens the next website.

The overall run time per macro is about 40 minutes (pauses of about 91 seconds).

I am using the loop button and it appears error up anywhere between 10 and 20 loops.



Yeah, just saw this error as well today; running 3.1.9. 355 line macro


Do you guys use other browser at the same time the script is running or watch videos(youtube etc. or in an app)?
I figured if I leave the laptop alone I do not stuck upon this error. But I stuck on freezing without any error written to log.
And I can’t figure out if this is the same error with a little different indication or not.



I am using it in a browser by itself. Nothing else running on the computer!



Just looked in the extensions errors console and saw

console.error(chrome.runtime.lastError.message + ', ’ + method + ', ’ + JSON.stringify(args));


I consistently get this error when using the “type” or “sendKeys” command with a textarea, when the value to type is very long (10,000+)
I am then using the following:

  "Command": "storeEval",
  "Target": "\"\\n50,000 extra chars:\\n\" + (new Array(1001).join(\"xyzab1234567890 xyzab1234567890 xyzab1234567890X,\\n\"))",
  "Value": "value50kCharacters"
  "Command": "type",
  "Target": "id=memo_field",
  "Value": "${value50kCharacters}"

HW specs: Macbook pro 2018; chrome 70.0; Kantu browser automation 3.3.3
Hope this helps in resolving it!


Hi @paulklinkenberg - this is a good test case, thanks!