Conditions Stopped Working

There were some problems with version 2.1.5 indeed. You would loose conditions if you had more than 50 and thus were forced to use text view.
These issues have now been resolved, so the issue you are having now (conditions not working) is probably related to something else. The first thing I would like you to check if if you see any relevant JS errors on your page. It could help to quickly run trough this troubleshooting guide and let me know what you find: https://conditional-fields-cf7.bdwm.be/docs/troubleshooting/does-not-work-with-a-third-party-theme-or-plugin/

I do get this is the console:

Uncaught TypeError: Cannot read properties of undefined (reading 'get')
    at Object.get_simplified_dom_model (scripts_es6.js:1229:24)
    at wpcf7cf_reload_dom (scripts_es6.js:72:27)
    at Object.get_nested_conditions (scripts_es6.js:1143:9)
    at ./js/scripts_es6.js.Wpcf7cfForm.updateGroups (scripts_es6.js:463:38)
    at new Wpcf7cfForm (scripts_es6.js:228:10)
    at HTMLFormElement.<anonymous> (scripts_es6.js:1532:24)
    at Function.each (jquery.min.js:2:3003)
    at s.fn.init.each (jquery.min.js:2:1481)
    at ./js/scripts_es6.js (scripts_es6.js:1531:23)
    at __webpack_require__ (bootstrap:19:1)

If I revert to a backup running 2.1.3 and clear my cache everything works fine, once I go back to 2.1.6 the problem returns. Specifically, the form loads, and everything outside of groups works, the form will submit, send the email and log to flamingo. I have not changed anything on the site other than running updates for months.

Don’t take this wrong, it is just an observation about troubleshooting guide’s that suggest sites with 50+ plugins, some that are required for things to work properly in the first place, can just be disabled to test a plugin – my experience is that the easiest way to handle broken plugins after an upgrade is to simply restore the last working version and edit the file so it will not auto-update, which is much faster and easier. I can then check back at a later date, when usually a newer version does fix the issue. The other option is to just switch to another plugin offering the same function that is not broken, also faster and easier in most cases (though it would not be here due to the number of conditions in use).

Maybe some kind of caching or JS optimisation plugin that’s causing trouble?

Do you have a link to your page?

Could you run this code in your console?

Object.getOwnPropertyDescriptor(Element.prototype, "children")

It should return an object. If it returns undefined or an error, this might mean that your browser is not supporting it (Internet Explorer), or that some code on your website has somehow removed the property.

Version 2.1.4 includes a change that allows the use of the name “children” for a field. Prior to this update is was impossible to use children as a name. This change seems to somehow interfere with your current setup. I’m eager to find out what is causing the conflict, so if you can give me a basic setup (minimum amount of plugins and themes) that causes the same problem, that would be very helpful for finding a fix.

That does return undefined.
I spent over an hour looking at some (recently updated) plugins, but with over 60 in use and more than a few required for the site to work, I ended up rolling back to 2.1.3, which works fine even with WP core fully up to date. I cannot easily provide a link, the form is private and deals with sensitive data. I am still fine trying to help, the site is somewhat modified, with many pages driven by custom php code, but that form itself only uses the Dynamic Text Extension plugin and CF7/Flamingo, which are not modified.

Interesting. Does it also return undefined when you open your console on any other website? (for example this one)

Both here and on my site running 2.1.3 I get no errors, and this is returned:
{set: undefined, enumerable: true, configurable: true, get: ?}

Wait, what? On the site where you are running version 2.1.3 Object.getOwnPropertyDescriptor(Element.prototype, "children") doesn’t return undefined?

But once you update the plugin to version 2.1.6, and you enter Object.getOwnPropertyDescriptor(Element.prototype, "children") in the console, it returns undefined?

Is that correct?

Hmm.
Sorry.
Maybe I did something funny (like was on a different site somehow) when I got the:
{set: undefined, enumerable: true, configurable: true, get: ?}

Because now it is undefined when using either 2.1.3 or 2.1.6.
I have both backed up locally and can ftp them in as needed (or use WP Rollback).

OK, so this means that a piece of code on your website is removing an essential DOM function from JavaScript. Not sure if you are familiar with JavaScript, but removing base functionality from JavaScript seems like a very sketchy business.

One extreme example would be to execute this code in a plugin: delete Object
This piece of code which might seem totally harmless will cause your entire website to crash.

Now, I’m guessing that there’s a piece of code on your website, that is doing something like this: delete Object.getOwnPropertyDescriptor. I would scan for a line like this, or any line doing funky things to the Object.getOwnPropertyDescriptor, and see if removing that line fixes your problem.

How would I go about scanning for something like that, nothing shows up in the source.

You would need to download your entire WordPress folder, and open it with a text editor like Visual Studio Code (which is free), then you can easily enter a search term and it will show you all the matching pieces of code in all your files.

OK
Notepad++ does it also I see, the folder is already in my local network.

delete Object.getOwnPropertyDescriptor
does not show up at all

Object.getOwnPropertyDescriptor
shows up over 600 times, often in the includes folder js files
It also shows up in plugins, but they are mainstream plugins and disabling them did not change the issue.

Is there a more specific or alternate search I can run?

It may be worth noting that there are no other problems with the website that has been running since 2013, so while I am not disputing the fact that other websites I checked are not returning undefined, it is not ‘crashing my entire website’ either, only your newer plugin versions are affected, everything else is and has been fine.

could you maybe email me the url of your website privately? You can find my email address on bdwm.be

If not, I’m wondering if Object.getOwnPropertyDescriptor returns anything other than ? getOwnPropertyDescriptor() { [native code] }

I’m also interested in the output of these commands:

Element

Element.prototype

Object.getOwnPropertyNames(Element.prototype)