Localhost is currently unable to handle this request. HTTP ERROR 500

iam error in installing OJS

localhost is currently unable to handle this request. HTTP ERROR 500

here is my error log

can anyone help me?

[Sat May 09 20:44:05.579495 2020] [php7:warn] [pid 8040:tid 1932] [client ::1:57718] PHP Warning: Declaration of InstallHandler::validate($request) should be compatible with PKPHandler::validate($requiredContexts = NULL, $request = NULL) in C:\xampp\htdocs\JHEI\lib\pkp\pages\install\InstallHandler.inc.php on line 48
[Sat May 09 20:44:08.076092 2020] [php7:warn] [pid 8040:tid 1932] [client ::1:57718] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\JHEI\cache\t_compile\e8ea13aa559bf8604ca823015b397a28d8666486^28682bb3d6b6e750ebd3d458abc8f92b4da9ea9f_0.app.headerusernav.tpl.php on line 136, referer: http://localhost/jhei/index.php/index/install/install
[Sat May 09 20:46:31.641707 2020] [php7:warn] [pid 8040:tid 1936] [client ::1:57733] PHP Warning: Declaration of InstallHandler::validate($request) should be compatible with PKPHandler::validate($requiredContexts = NULL, $request = NULL) in C:\xampp\htdocs\JHEI\lib\pkp\pages\install\InstallHandler.inc.php on line 48, referer: http://localhost/jhei/index.php/index/install/install
[Sat May 09 20:46:31.978499 2020] [php7:error] [pid 8040:tid 1936] [client ::1:57733] PHP Fatal error: Uncaught Error: Call to undefined function mysql_connect() in C:\xampp\htdocs\JHEI\lib\pkp\lib\adodb\drivers\adodb-mysql.inc.php:456\nStack trace:\n#0 C:\xampp\htdocs\JHEI\lib\pkp\lib\adodb\adodb.inc.php(558): ADODB_mysql->_connect(‘localhost’, ‘root’, ‘’, ‘’)\n#1 C:\xampp\htdocs\JHEI\lib\pkp\classes\db\DBConnection.inc.php(151): ADOConnection->Connect(‘localhost’, ‘root’, ‘’, NULL, false)\n#2 C:\xampp\htdocs\JHEI\lib\pkp\classes\db\DBConnection.inc.php(126): DBConnection->connect()\n#3 C:\xampp\htdocs\JHEI\lib\pkp\classes\db\DBConnection.inc.php(113): DBConnection->initConn()\n#4 C:\xampp\htdocs\JHEI\lib\pkp\classes\db\DBConnection.inc.php(55): DBConnection->initCustomDBConnection(‘mysql’, ‘localhost’, ‘root’, ‘’, NULL, false, ‘utf8’)\n#5 C:\xampp\htdocs\JHEI\lib\pkp\classes\install\PKPInstall.inc.php(76): DBConnection->__construct(‘mysql’, ‘localhost’, ‘root’, ‘’, NULL, false, ‘utf8’)\n#6 C:\xampp\htdocs\JHEI\lib\pkp\classes\install\Installer.inc.php(178): PKPInstall->preInstall()\n#7 C:\xampp\htdocs\JHEI\lib\pkp\cl in C:\xampp\htdocs\JHEI\lib\pkp\lib\adodb\drivers\adodb-mysql.inc.php on line 456, referer: http://localhost/jhei/index.php/index/install/install

Hi, @Aista_Wisnu_Putra,

The most probable reason is that you are using mysql driver instead of mysqli with PHP7+

Thanks so i must install the mysqli with PHP7+ ok?

mysqli should be shipped by default with PHP 7+. Choose to use this driver during installation.