Fatal error: Uncaught exception 'PDOException' in Pattern Screen

I am attaching screenshots of Pathauto "Pattern" page that show me the error -

( ! ) Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in C:\wamp\www\includes\database\database.inc on line 2139

( ! ) PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in C:\wamp\www\includes\database\database.inc on line 2139

The settings page works normally. That screenshot is attached as well.

I installed Global Redirect and Pathlogic modules recently so I uninstalled those, cleared caches and tried to reinstall Pathauto but I get the same error.