I sent many messages regarding the same problem to admin. But he isn't able to answer me for months what is the problem. IMO I did nothing what caused the blocking. But the support here is nothing more than shit by the forum owners.
BTW the message which appears is the following:
columbus, you do not have permission to access this page. This could be due to one of several reasons:
Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation.