The issue has been resolved in reCaptcha. The login form should now work again in all browsers.
Posted May 06, 2024 - 18:36 UTC
Investigating
Some users with newer versions of Firefox are reporting problems logging in to Overleaf. After submission, the login form reports the error: "captcha check failed: challenge expired". This seems related to compatibility problems between Firefox and reCaptcha. We are currently looking for solutions. For the moment, the workaround is to use another browser.