If you're trying to solve a CAPTCHA through the onion but it's missing/invisible, try the workaround in >>4626
Make sure to open the devtools window before opening the captcha window, or else you'll have to refresh the page.
You can also replace the image's URL with http instead of https as a fix.
Details for the fish: seems like jschan fetches the captcha image with an URL containing https, which doesn't work over the onion.
It doesn't happen constantly, but often enough to be troublesome. It happened to me while posting this.
Looking at https://gitgud.io/fatchan/jschan/-/blob/v1.4.1/models/pages/captcha.js?ref_type=tags line 54:
.cookie('captchaid', captchaId.toString(), {
'secure': production && secureCookies && (req.headers['x-forwarded-proto'] === 'https'),
'sameSite': 'strict',
maxAge,
})
.redirect(`/captcha/${captchaId}.jpg`);
The secure field in line 55 may be why it converts the URL to https.
In particular, the code req.headers['x-forwarded-proto'] === 'https' may be the culprit, which seems to check the HTTP request header x-forwarded-proto for the value https, therefore setting secure to true (if production and secureCookies are also true, which
I'm assuming so).
Perhaps it's an issue with some proxy config of yours?
Note that this code is also present in jschan's latest master (bd48d527).