I've tried to set up a new forum today and when it asks me to validate, no captcha is displayed. In the console it shows there's an error with captcha on line 41.
What precisely is your issue? Is it when trying to create your forum; or when someone tries to register a new account? May you post a screenshot of the error message (if any) you get?
I should mention that these screenshots were taken in google chrome, but the same thing happens in firefox and IE and maintains even when adblock is disabled.
Now speaking to IT where I am to make sure scripts aren't being blocked on my end. If someone could verify if this is just me by creating a new forum, that'd really help