Yes, it's a problem with the captcha system. Sometimes the generated word is bigger than the background. A fix is on the road.
If you don't need / don't want captcha, you can disable it at Admin Panel -> Configurations.
Rafael [originally posted on jforum.net by Rafael Steil]
OK,i according to this method update ,the problem was resolved
thank you !
but i hope you can explain cause [originally posted on jforum.net by Anonymous]