- Patch #11600 by jhriggs: the module_load_all() function will currently behave unexpectedly if a module cannot be found (has been removed, renamed, etc). Once one module fails to load, all subsequent modules will not be loaded due to a short circuit condition when performing a boolean AND.

includes/module.inc

@@ -149,7 +149,7 @@ function module_load_all() {
   $list = module_list();
   $status = true;
   foreach ($list as $module) {
-    $status = $status && module_load($module);
+    $status &= module_load($module);
   }
   return $status;
 }