CAPTCHA not working in wiki

When I try to edit a wiki-page, the CAPTCHA gives this message:

Please upgrade to a supported browser to get a reCAPTCHA challenge.
Why is this happening to me?

Yesterday it worked well, I use Chrome (one of the supported browsers) / Windows 10

What version of Chrome do you have? The page notes that reCAPTCHA only supports the two most recent major versions of each supported browser.

Version 86.0.4240.111, updated today.

After restarting my computer, I could edit the wiki yesterday. But I had to do several CAPTCHA picture galeries.
This morning I get the message from >1 FAMeulstee: again.

Okay, thanks.

Do you have JavaScript enabled in your browser? Do you have any extensions/plugins on your browser?

>5 kristilabrie: Javascript is enabled, extensions: Adblock Plus and virusprotection by F-Secure.

Now you mention extensions, I recently turned off Flash (got a message from Chrome to turn it off, as it ends this year). Enabling Flash again does seem to do the trick.

I tried to reproduce this with disabled Flash and wasn't able to. I would lean towards your Adblock extension being the culprit here, though I'm not sure why re-enabling your Flash worked. Try disabling Flash and your Adblock Plus and see if that works, too, maybe?

>7 kristilabrie: I have librarything.com on the whitelist of the Adblocker.
Turned Flash off again and now CAPTCHA still works... I will look again tomorrow morning and if it still works okay, I will close the topic.

It looks like turning on Flash was only coincidence, as this morning all is normal.
Closing the topic.

Great! Glad the issue was found.