After disabling and uninstalling memcached module, I get this PDOException and WSOD? I´ve cloned my production site in a local Xampp installation.
My site has Memcached installed (in the server and I´ve got the drupal memcache module installed).

But I´ve got this error at my local site:


  You must enable the PECL memcached or memcache extension to use
  memcache.inc


(this is repeated at least 30 times, so that line is printed about 30 times at the top of every page).

Now, I´ve disable and unninstalled memcache at my local installation, and the error is still there.

I´ve tried after that deleting the additional settings added to my settings config file:


  $conf['cache_backends'][] = 'sites/all/modules/memcache/memcache.inc';
  $conf['cache_default_class'] = 'MemCacheDrupal';
  $conf['memcache_key_prefix'] = 'memcache_sitio';
  $conf['cache_class_cache_form'] = 'DrupalDatabaseCache';


But if I do eliminate those lines (after I´ve uninstalled -not only disabled- memcached module), I get WSOD and this error:


  Fatal error: Uncaught exception 'PDOException' with message
  'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\database\database.inc:2139
  Stack trace: #0
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\database\database.inc(2139):
  PDOStatement->execute(Array) #1
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\database\database.inc(664):
  DatabaseStatementBase->execute(Array, Array) #2
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\database\database.inc(2318):
  DatabaseConnection->query('SELECT expire, ...', Array, Array) #3
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\lock.inc(167):
  db_query('SELECT expire, ...', Array) #4
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\lock.inc(146):
  lock_may_be_available('schema:runtime:...') #5
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\bootstrap.inc(405):
  lock_acquire('schema:runtime:...') #6 C:\Users\Victoria in
  C:\Users\Vic\Desktop\XAMPP\htdocs\drupal\includes\database\database.inc
  on line 2139


Please note that I´ve deleted all cache, tried disabling (and enabling) all performance options, and I´ve run run cron more than once.

What should I do? Thanks!
Each time I saw the "Mysql server has gone away" error, it was caused by the max_allowed_packet setting (in the my.ini setting file) that was too small.