500 Errors for crin.org

[chris]

There have been a lot of 500 errors today and they appear to be related to lines like this in /var/log/php/error.log:

[16-May-2017 17:33:08 Europe/London] PHP Fatal error:  Call to undefined function entity_translation_language_load() in /var/www/prod/docroot/includes/menu.inc on line 593

The section on the file in question:

 538 
 539 /**
 540  * Loads objects into the map as defined in the $item['load_functions'].
 541  *
 542  * @param $item
 543  *   A menu router or menu link item
 544  * @param $map
 545  *   An array of path arguments; for example, array('node', '5').
 546  *
 547  * @return
 548  *   Returns TRUE for success, FALSE if an object cannot be loaded.
 549  *   Names of object loading functions are placed in $item['load_functions'].
 550  *   Loaded objects are placed in $map[]; keys are the same as keys in the
 551  *   $item['load_functions'] array.
 553  */
 554 function _menu_load_objects(&$item, &$map) {
 555   if ($load_functions = $item['load_functions']) {
 556     // If someone calls this function twice, then unserialize will fail.
 557     if (!is_array($load_functions)) {
 558       $load_functions = unserialize($load_functions);
 559     }
 560     $path_map = $map;
 561     foreach ($load_functions as $index => $function) {
 562       if ($function) {
 563         $value = isset($path_map[$index]) ? $path_map[$index] : '';
 564         if (is_array($function)) {
 565           // Set up arguments for the load function. These were pulled from
 566           // 'load arguments' in the hook_menu() entry, but they need
 567           // some processing. In this case the $function is the key to the
 568           // load_function array, and the value is the list of arguments.
 569           list($function, $args) = each($function);
 570           $load_functions[$index] = $function;
 571 
 572           // Some arguments are placeholders for dynamic items to process.
 573           foreach ($args as $i => $arg) {
 574             if ($arg === '%index') {
 575               // Pass on argument index to the load function, so multiple
 576               // occurrences of the same placeholder can be identified.
 577               $args[$i] = $index;
 578             }
 579             if ($arg === '%map') {
 580               // Pass on menu map by reference. The accepting function must
 581               // also declare this as a reference if it wants to modify
 582               // the map.
 583               $args[$i] = &$map;
 584             }
 585             if (is_int($arg)) {
 586               $args[$i] = isset($path_map[$arg]) ? $path_map[$arg] : '';
 587             }
 588           }
 589           array_unshift($args, $value);
 590           $return = call_user_func_array($function, $args);
 591         }
 592         else {
 593           $return = $function($value);
 594         }
 595         // If callback returned an error or there is no callback, trigger 404.
 596         if ($return === FALSE) {
 597           $item['access'] = FALSE;
 598           $map = FALSE;
 599           return FALSE;
 600         }
 601         $map[$index] = $return;
 602       }
 603     }
 604     $item['load_functions'] = $load_functions;
 605   }
 606   return TRUE;
 607 }
 608 

Peter, is the the cause of the 500 errors or is it a symptom, or is it unrelated? Do you have an idea what is going on here?