"The solution to the task was incorrect" error

When members try to retrieve their password, they encounter a “The solution to the task was incorrect” error. I disabled the plugin and now everything works fine. However, I really like the Sweet Captcha plugin and would hate to install a different captcha plugin due to this issue. Is there any way this can be resolved so I can continue using Sweet Captcha?

Thanks!

https://www.ads-software.com/plugins/sweetcaptcha-revolutionary-free-captcha-service/