Cache Issue

[eagleman]

Hello

I need your help please when i try to clear cache i get on backend ERRO 500 and php side 

2574#0: *119607 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Class 'Tools' not found in /var/www/vhosts//httpdocs/classes/db/Db.php:794
Stack trace:
#0 /var/www/vhosts//httpdocs/config/alias.php(48): DbCore->escape('configuration', false)
#1 /var/www/vhosts//httpdocs/config/alias.php(53): pSQL('configuration')
#2 /var/www/vhosts//httpdocs/classes/Configuration.php(155): bqSQL('configuration')
#3 /var/www/vhosts//httpdocs/classes/Configuration.php(209): ConfigurationCore::loadConfiguration()
#4 /var/www/vhosts//httpdocs/classes/PrestaShopAutoload.php(171): ConfigurationCore::get('PS_DISABLE_OVER...')
#5 /var/www/vhosts//httpdocs/classes/PrestaShopAutoload.php(130): PrestaShopAutoload->generateIndex()
#6 [internal function]: PrestaShopAutoload->load('Tools')
#7 /var/www/vhosts//httpdocs/config/config.inc.php(85): spl_autoload_call('Tools')

#8 /var/www/vhosts//httpdocs/admin/index.php(42): require('/var/www" while reading response header from upstream

Thank you