But What about this question?
»And I can not se topics and posts when I am not logged in. Why?»
Because the registration was incomplete and you don't have proper permission. I think you don't even have wpForo Usergroup. You can check it in Dashboard > Users > Your Profile admin page, scroll and find the wpForo usergroup option, set it admin and save it.
In any case you've tried disable all plugins and changing theme don't help, please send admin login details to support[at]gvectors.com email address. We'll login and check within next 12-24 hours.
Don't forget delete all caches and wpForo cache in Dashboard > Forums >Dashboard admin page before checking it ( [Delete all caches] button) .
Can you @robert log in to my site and check these things?
Please deactivate all other plugins. Make sure all works fine on your website and send admin login details to support[at]gvectors.com email address.
I havw now tried to disable all plugins, but there still is problems. I have sent you the login details now.