enable Rule module with fatal error I use drupal 7.26 and try to install Rules(7.x-2.6) with drush (drush en rules -y)

I can not visit my drupal site Now.

I install Xdebug. this follow is error detail:

Fatal error: Class name must be a valid object or a string in /Users/tangmonk/MyGit/Drupal/daxuebao/includes/common.inc on line 7837

#   Time    Memory  Function    Location
1   0.0011  240392  {main}( )   ../index.php:0
2   0.0155  656312  drupal_bootstrap( ) ../index.php:22
3   0.2055  5039280 _drupal_bootstrap_full( )   ../bootstrap.inc:2260
4   0.6304  21000048    module_invoke_all( )    ../common.inc:5158
5   0.6328  21061544    call_user_func_array ( )    ../module.inc:895
6   0.6328  21061744    rules_init( )   ../module.inc:895
7   0.6343  21098688    rules_invoke_event( )   ../rules.module:12
8   0.6343  21099144    rules_get_cache( )  ../rules.module:969
9   0.6666  22764416    RulesEventSet::rebuildEventCache( ) ../rules.module:333
10  0.7564  25670784    rules_config_load_multiple( )   ../rules.plugins.inc:764
11  0.7564  25670872    entity_load_multiple_by_name( ) ../rules.module:804
12  0.7564  25670936    entity_load( )  ../entity.module:252
13  0.7564  25671016    entity_get_controller( )    ../common.inc:7804
Try going to http://yoursite.com/update.php and execute the form submit.

If this does not work, you must:


disable rules by SQL command:

UPDATE system SET status = 0 WHERE system.name = 'rules';
Execute drush cc all
Active drush again:

Drush en rules -y