Hi,
i have installed jForum 2.3.5 in my localhost and in the live server. The captcha verification is working on my localhost, but it is not working on my server. So, currently i have disabled the captcha verification. Any suggestion, how to fix this problem?

Hi, welcome to the community.
Please check your web container's log file(for example, Tomcat's catalina.out)
And see if there are some error messages as a hint for what's going wrong there.
Also, you'd better provide some environment information like OS version, Java version, etc.