[Issue #513] Script freezes unexpectedly with no error written to log. Manual pause/resume brings it back

I have the same problem… Do you think you will manage to fix it soon ?
Thank you for all you do, I use Kantu for three months and I really enjoy !

I face this EVERY DAY. And the amount of it just depends on how many times I come back to refresh the page. Kantu can not be left unattended.

Most kantu freezes occur when an internet site loads slowly or doesn’t load completely unfortunately this is Kantu’s weak point the bad control of the browser tabs, it takes very little and freezes, otherwise with imacros this never happened I have macros who work me 24 hours a day without ever stopping or crashing.

I have this issue on 50/50 mbps connection, on 15/2 and on 5/5. In my experience it has nothing to do with internet connection. And if you think about it should not have. But if this is your perception if the issue I hope it could be valuable to developers.

Usually in cases that I have noticed that Kantu stops when a site does not load completely but it has many other bugs because often I get the message that “Kantu is not connected to the tab”.
I love Kantu but I find it difficult to automate because of the many problems that appear during use and some problems seem unpredictable and random.
I repeat I love Kantu and I would like it to become the best automation program so that I can let it work without worries to find it blocked or with errors.

Fully agree with you on this.

If you run a macro and the connection internet down or site do not load Kantu remain stucked to wait the loading of page (if the connection is down site do not load never).

This is a big problem because sometimes a site can load slowly or can not load and not have sense that Kantu remain stucked.

Imacros in this case continue to work, with page offline too, continue and give errors but not remain stucked.

Is it possible that any admin tells us if this problem will be solved soon ?

I’ve been battling with this issue every day. Still not repeatable, but this might be a clue. The way I’m running Kantu is with a parent macro and several “child” macros that utilize the run command. With each of my child macros, I hang a js library off of global (storeEval | window.myLibrary={myFunc={},…}). This works well in that I can re-use these small functions to do more complex processing more quickly. One instance of the hang/freeze problem occurs when mylibrary seemingly disappears from the global scope. Here are a few commands from the top of my child macro:

  "Command": "selectWindow",
  "Target": "tab=open",
  "Value": "https://my.domain.com/${profile}/address"
  "Command": "waitForPageToLoad",
  "Target": "1000",
  "Value": ""
  "Command": "storeEval",
  "Target": "window.myLibrary={myfunction1:function(){...},myfunction2:function(){...},...}",
  "Value": ""
  "Command": "storeEval",
  "Target": "window.myLibrary.myfunction1();",
  "Value": ""
  "Command": "storeEval",
  "Target": "window.myLibrary.myfunction2();",
  "Value": ""

This will run successfully 30 times, then it will hang on the last command shown. It will stay there until the full timeout limit is reached. Before the timeout is reached, I open up the Chrome console and ask it for myLibrary, and it returns undefined. Very strange, because the command just before it was successful.
Now then, this does not cover the full spectrum of situations in which the problem occurs, but it does highlight one instance and I hope this might support the efforts to fix this situation.

Note: I’ve installed v4.1.6 because this and other issues with more recent releases were bringing me to a halt.

Chrome. Kantu v 4.1.6

My macro became unresponsive, so I immediately opened up the browser console and saw errors. Finally, the macro timed out. Here is the console dump:

background_csv_editor_desktop_screenshot_editor_popup_vision_editor.js:1168 pReady - error Objectmessage: "Disconnected"proto: Object
(anonymous) @ background_csv_editor_desktop_screenshot_editor_popup_vision_editor.js:1168
popup.html#/:1 Unchecked runtime.lastError: Specified native messaging host not found.
popup.js:19487 getOcrCommandCounter - read
popup.html#/:1 Uncaught (in promise) Objectmessage: "Disconnected"proto: Object
popup.html#/:1 Unchecked runtime.lastError: Specified native messaging host not found.
popup.html#/:1 Uncaught (in promise) Objectmessage: "Disconnected"proto: Object
popup.js:1019 Uncaught (in promise) Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: Error: token expired
at Player.__errLog (popup.js:1019)
at popup.js:913
at popup.js:792
popup.js:26090 Error: Error: macro ‘My Macro Name’ timeout 1800s (change the value in the settings if needed)
at Player.__errLog (popup.js:1031)
at Player.stopWithError (popup.js:713)
at Countdown.callback (popup.js:8439)
at Countdown.runCallback (popup.js:26087)
at popup.js:26045
runCallback @ popup.js:26090
(anonymous) @ popup.js:26045
popup.js:26045 [Violation] ‘setTimeout’ handler took 155ms
popup.js:979 Uncaught (in promise) Error: Stop reason: ERROR
at popup.js:979

Kantu needs another automation tool to make it work. Anybody knows chrome extension that would reload the page IF it has not been reloaded for 3 minutes?
upd. I’ve found extensions to be shady and not able to work on a domain basis. So far I’m using violentmonkey to inject page refresh code. If somebody need it I post it here
Replace www.example.com or add more domains you need to refresh on and change the default timeout (120 sec).

// ==UserScript==
// @name     Auto-Refresh
// @include  https://www.example.com/*
// ==/UserScript==

setTimeout(function(){ location.reload(); }, 120*1000);


There are more addons to auto refresh, i found this but there are more and more

Kantu is a fantastic tool but sometimes i find it stucked and do not respond (whether it is started via the command line or is started manually) now i use taskkill to close browser stucked and reopen it.

In my testcase i see when site do not load Kantu stucked and is a big problem because stuck totally my browser the unique good solution for me is taskkill and restart macro with a batch file.

@newuserkantu Addons do not work on domain basis. So I click and URL changes and that’s it auto refresh and it’s clones are useless. I’m on the same website but the page is different so AuRef does not pick it up. UserJS injects refresh code on every page from this domain. And you can adjust it as well.


I’m sorry but I can’t help you, I can’t understand the problem.

I use the taskkill and the restart of the macro from the command line for the cases in which it does not answer to the commands (imposed 10 minutes of control, if firefox is open from 10 minutes it means that the macro is blocked) then the taskkill starts automatically closes firefox and restarts the macro, I don’t know if it’s a solution that you can use for your problem too.

Dude I’m ok. )) I worry about you. Command line gifts a bunch of other errors I’m fed up to deal with.

Just a note that we are reading the discussion here with great interest. We are still looking for a way to recreate this bug reliably (so we can then debug and fix it). We know the issue exists, but it is very hard to trigger it reliably.


Try a macro with open command and during the loading of the site stop/block the connection (you can use a proxy or vpn to do this) in this case Kantu remain stucked, do not continue with the macro, do nothing, it’s a big problem because do not continue and do not contnue with the new command, in this case i must force with taskkill otherwise firefox rest open stucked forever.

This problem usually appaire when you use a proxy and during the loading of page the proxy lost connection, Kantu rest stucked and do not continue.

Will be usefull a command to force kantu tu continue to work (with error too) but not rest stucked, a force to continue the macro or a jump last command stucked and continue in every case, in this mode it’s possibile to add at the end of macro an autoclosing tabs to prevent stucked macro.

I use Kantu with firefox.

@admin I tried to send you test macro via webform but it gives me error. I guess it does not like text json format.

# Server Error in '/' Application.

## *Runtime Error*

**Description:**  An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine. 

**Details:**  To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".

`<!-- Web.Config Configuration File -->

        <customErrors mode="Off"/>

**Notes:**  The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's &lt;customErrors&gt; configuration tag to point to a custom error page URL.

`<!-- Web.Config Configuration File -->

        <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>

Hitting refresh doesn’t work 100% of the time; sometimes it does, other times not.

Frustrating for us and the devs, I’m sure. Honestly, we need this fixed before new features are added.

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@admin, I have a 75mg (rather long) video demonstrating aspects of this issue. I’d like to share with you without posting on the forum or making public. How can I share this with you?