I enable one module and then I got the error message as follow. The module maintainer believes that this has nothing to do with the module at all, and as the error message seems to indicate some problem with the admin module, I figure I should report it here.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT menu_links.* FROM {menu_links} menu_links WHERE (module = :db_condition_placeholder_0) AND (router_path = :db_condition_placeholder_1) ; Array ( [:db_condition_placeholder_0] => system [:db_condition_placeholder_1] => admin/config/content ) inadmin_landing_page_access() (line 164 ofC:\wamp\www\sites\all\modules\admin\admin.module).



This could be a PDO buffer issue, like the one seen in admin_menu. See issue #1302240-4: Enable admin_menu with toolbar give MySQL server has gone away:.

Thank you very much tomogden! That's very, very helpful. I'm going to see if that applies to my case once I know how to increase the buffer allowance.