Can't Access Manager "captcha not configured properly"

MODx Evolution Version 1.0.12

Out of the blue a clients' website is getting the error

captcha not configured properly

This happens when they try to login as a web user or when I try to login as manager user. I can't find a solution to fix this within the forum.

I've noticed that there is a new version of MODx available now. Should I just upgrade the site to version 1.0.13, or does someone have a solution for this?

Thanks in advance for any help.

If anyone one runs into this problem, empty the sessions folder and ensure that MySQL 5.5 is running.

Thank you to Jako and Patrick for all your help.

See thread here:

https://forums.modx.com/thread/90468/receiving-039-captcha-039-error-should-i-just-upgrade-to-1-0-13#dis-post-498065