On activating protected node, guest can't browse the site anymore (unexpected error)

When i activate Protected Node the Guest gets Unexpected Error on every link in the site. On deactivating everything works again.
I get this messages from Database Log:
Warning: Illegal offset type in isset or empty in drupal_lookup_path() (Zeile 158 von /home/devkath/public_html/includes/path.inc).
Notice: Array to string conversion in DatabaseStatementBase->execute() (Zeile 2139 von /home/devkath/public_html/includes/database/database.inc). (3x times in a row)
PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' 'dev.stlaurentius.ch', 'overlay-ajax/page_bottom', '', 'overlay-ajax/page_botto' at line 1: SELECT source FROM {url_alias} WHERE alias = :alias_scheme, :alias_host, :alias_path, :alias_query, :alias_full_path, :alias_base_path, :alias_query_array, :alias_url_full, :alias_url, :alias_url_decoded, :alias_base_dir, :alias_filename, :alias_directory, :alias_normal_path, :alias_path_alias, :alias_args, :alias_menu_item, :alias_is_cacheable AND language IN (:language, :language_none) ORDER BY language ASC, pid DESC; Array ( [:language] => de [:language_none] => und [:alias_scheme] => http [:alias_host] => dev.stlaurentius.ch [:alias_path] => overlay-ajax/page_bottom [:alias_query] => [:alias_full_path] => overlay-ajax/page_bottom [:alias_base_path] => / [:alias_query_array] => Array ( ) [:alias_url_full] => dev.stlaurentius.ch/overlay-ajax/page_bottom_ [:alias_url] => http://dev.stlaurentius.ch/overlay-ajax/page_bottom [:alias_url_decoded] => /overlay-ajax/page_bottom_ [:alias_base_dir] => cache/normal/dev.stlaurentius.ch/ [:alias_filename] => cache/normal/dev.stlaurentius.ch/overlay-ajax/page_bottom_ [:alias_directory] => cache/normal/dev.stlaurentius.ch/overlay-ajax [:alias_normal_path] => overlay-ajax/page_bottom [:alias_path_alias] => overlay-ajax/page_bottom [:alias_args] => Array ( [0] => overlay-ajax [1] => page_bottom [2] => ) [:alias_menu_item] => Array ( [page_type] => page_bottom [page_id] => [path] => overlay-ajax/% [load_functions] => Array ( [1] => ) [to_arg_functions] => [access_callback] => user_access [access_arguments] => a:1:{i:0;s:14:"access overlay";} [page_callback] => overlay_ajax_render_region [delivery_callback] => [fit] => 2 [number_parts] => 2 [context] => 0 [tab_parent] => [tab_root] => overlay-ajax/% [title] => [title_callback] => t [title_arguments] => [theme_callback] => [theme_arguments] => Array ( ) [type] => 0 [description] => [position] => [weight] => 0 [include_file] => [href] => overlay-ajax/page_bottom [tab_root_href] => overlay-ajax/page_bottom [tab_parent_href] => [options] => Array ( ) [access] => 1 [localized_options] => Array ( ) [original_map] => Array ( [0] => overlay-ajax [1] => page_bottom ) [status] => 200 [extra_arguments] => ) [:alias_is_cacheable] => 1 ) in drupal_lookup_path() (Zeile 176 von /home/devkath/public_html/includes/path.inc).

Also if i try to upload images in a content type thumbnail doesnt work with activated protected node.