security token was missing
 

Hello,
WHen I click some link (direct to other site) on my board I receive such error:

What can I do now?

Here's the thread on how to fix it. It is most like a template that just needs the securitytoken added - Implementing CSRF Protection in modifications

Mmmm...so to which one template I must add this code?
This error I receive after when click some link to other site (a normal link in posts).

I don't know which template. You really need to go through your edited templates in the style - they will be in red - and do a View History and then Compare your template to the default Jelsoft template and see where you are missing a securitytoken. The other option is that it is from a modification - turn them off and see if you still get the problem. If you still get the problem with them off, then it is your template. If you don't get the problem when they are off, then it is a plugin.

Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php