404 Not Found

The extension you were using probably sent a permanent moved header with the redirect. So it's probably browser cached. Clear your browsers cache data (e.g. browser history). If you've Joomla cache enabled also be sure to clear Joomla cache. There is no code in CB doing that. We do not allow submit endpoints to be overridden like that so only way for that to happen is 3rd party extension intercepting the URL during routing and redirecting away.

So I did all that everyone has asked me to do. In fact I uninstalled Chrome. Deleted the folder and started fresh again.
I cleared the cache in Joomla and also cleared the Cache in google chrome again.

The same thing happens. But the strangest thing is that some people can sign up and others get the same 404 error. I know that when one of your's signed up it worked fine. I even sent a ticket to my hosting company and they could sign up without a problem.

Not Found
The requested URL was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

and the url reads after you press the submit button iaabo27.org/www.fbi.org I had Brute force installed and I unpublished it. I also had Admin Exile installed which was where the person was pointed to that url
when they tried logging in. I also uninstalled and deleted the folder.

Just to go a bit further. The admin must approve all sign ups. I also had an email sent to them telling them that the admin had to approve them, but that stopped working awhile back.

After they sign up the pop:

<b>Your registration has been received.</b>
<br>Once the registration has been approved<br>
<br>you will receive notification. Then you will<br>
<br>able to log in</br>
Thank you.

is suppose show up.

But that doesn't show up either.

It's clearly something you've configured that's interrupting CB. I've no idea what as only you would know that given you configured it. Best I can suggest is start unpublishing non-core CB plugins and Joomla extensions 1 by 1 until the issue goes away. The redirect could be during Joomla user store process so it could easily be a Joomla system or user plugin trying to redirect. It could also be a custom auto action in CB Auto Actions that you may have configured redirecting away. It could even be an antispam block you've configured in CB AntiSpam. If you still can't find what's causing it you may want to consider starting your site over and being careful with what you configure.

some people can sign up and others get the same 404 error

My guess is that you've limited registrations to 1 per IP adress. That is why I referred to CB antispam plugin as it has this option.

Guess what...it is the SPAM. I found the redirect and fixed it. Then I tried it again and it didn't save the information of the new sign up. then I uninstalled it and now it works perfect. NOW what do I do about CBSpam. I need that to work so that I don't get 100 sign ups. I've entered the Site Key and the Secret Key to use V2 or V3 and they also don't work. I've looked at the doc's and nothing there tells me if there is a problem what to do.

What doesn't work? Captcha always failing? You need to be more specific. Please ensure everything installed is up to date. The automatic blocking functionality blocks based off the criteria you specifically configure it to use. It by default doesn't have a redirect URL either, which can not be an external URL.

This topic also belongs in the support forums so have moved your topic.