UPDATE: in the server of Pavel Sklenar the deal was in the following errors:

is_dir(): open_basedir restriction in effect. File(/) is not within the allowed path(s): (/[server_path]:/www/error-pages) in /[server_path]inc/classes/BxDolStorageLocal.php on line 140

Warning: file_exists(): open_basedir restriction in effect. File(/) is not within the allowed path(s): (/[server_path]:/www/error-pages) in /[server_path] /inc/classes/BxDolStorageLocal.php on line 140

The server has put the own value for this parameter by security reason.