[求助]突然后台进不去了，求助修复

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in D:wamp64wwweclassdbdb_mysqli.php:15 Stack trace: #0 D:wamp64wwweclassconnect.php(156): do_dbconnect('localhost', '', 'root', '', 'empirecms') #1 D:wamp64wwweadminecmsadmin.php(14): db_connect() #2 {main} thrown in D:wamp64wwweclassdbdb_mysqli.php on line 15

如何修复啊？急


Stack trace:
#0 D:wamp64wwweclassconnect.php(156): do_dbconnect('localhost', '', 'root', '', 'empirecms')
#1 D:wamp64wwweadminecmsadmin.php(14): db_connect()
#2 {main}
  thrown in D:wamp64wwweclassdbdb_mysqli.php on line 15
[10-Jul-2019 16:29:06 PRC] PHP Fatal error:  Uncaught Error: Call to undefined function mysqli_connect() in D:wamp64wwweclassdbdb_mysqli.php:15
Stack trace:
#0 D:wamp64wwweclassconnect.php(156): do_dbconnect('localhost', '', 'root', '', 'empirecms')
#1 D:wamp64wwweadminecmsadmin.php(14): db_connect()
#2 {main}
  thrown in D:wamp64wwweclassdbdb_mysqli.php on line 15
[10-Jul-2019 16:36:20 PRC] PHP Fatal error:  Uncaught Error: Call to undefined function mysqli_connect() in D:wamp64wwweclassdbdb_mysqli.php:15
Stack trace:
#0 D:wamp64wwweclassconnect.php(156): do_dbconnect('localhost', '', 'root', '', 'empirecms')
#1 D:wamp64wwweadminecmsadmin.php(14): db_connect()
#2 {main}
  thrown in D:wamp64wwweclassdbdb_mysqli.php on line 15