Question Problems after updating to 5.2

Ok,
I created a "registered user" for you:

Maybe I found the problem. The login works only via the main page login module, because the captcha isn't displayed in the forum, so you can't to enter the invoice result.
Test it, f it works if you disable your captcha plugin(s).
In your configuration report I see, you've chosen CAPTCHA Challenge for Users = 3 So I think, maybe my 3 test topics are pending messages and must be approved by a moderator (if yes please delete these).

I disabled the "Captcha - ReCAPTCHA" plugin. That didn't change anything though.
I also checked the setting "moderate new users", but it is set to 0, so that should work.
I changed the setting "captcha challenge for users" to 0, too. This shouldn't have been a problem as "display captcha" was already set to "for noone" (if I understand this correctly). Anyway, that also didn't help unfortunately.
Hmm - just to check - if topics would have to be moderated before they appear - where would I have to go to do this?

If topics should be moderated, you can set this also for single categories (see image). And pending messages will be displayed on the index page.

That seemed to have worked, and the posts in the forum are displayed again. However, it is not possible to post answers (redirects to 404 error message) or to create new topics (redirects to "current threads", but new thread does not exist).

That's not an error, because guests have no access for some things. But all your menus are available for guests and that's a misconfiguration, because the users think, they are logged in. But in fact, they are guests and therefore the 404 error because the guests have no rights for some actions.
Menu items like Unread, New Topic, No Replies, My Topics and Profile are default only for registered users available.

 

 

There are no pending message on the index page.
I did not try any of these actions (reply, new topic) as a guest, but with my admin account. I does not work for the admin, and it does not work for registered users.

I did not try any of these actions (reply, new topic) as a guest, but with my admin account. I does not work for the admin, and it does not work for registered users.

After login, I got no 404 errors on your page.

I can't make sense of your homepage. My browser tool and also the source code of your page shows all linked addresses with html at the end. But if you click on it, it will removed  this ending from the browser address.
Have you enabled this option in your Joomla SEO configuration? Or have you enabled the redirect plugin? If yes, disable this and test your page again.

It seems, your Joomla template shows no alert messages on top. Switch during the tests to the default template Protostar and read the message on top when you have tried to create a topic.