I had a similar problem on one install - turned out to be mod_version apache module is not enabled. This needs enabling. Or you need to edit .htacesss and take out those parts. Without it the site will 500. In this case this is a hosting issue.
Magento 2: Apache mod version not enabled/installed/allowed by host, causes 500 error on all pages due to failing .htaccess files
I also recommend using a check script to make sure you have everything you need. You should as Magento installed. But worth a check.
Here is one such script
https://github.com/sjanjic/magento2-check/blob/master/index.php
check.php
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
function result($value, $result)
{
if ($result) {
return array('css' => 'success', 'note' => $value . ': OK');
}
return array('css' => 'danger', 'note' => $value . ': FAIL');
}
function apacheModules()
{
$results = array();
preg_match('/([\d]+\.[\d]+\.[\d]+)/', apache_get_version(), $version);
$results[0] = array('css' => 'danger', 'note' => 'Version: ' . $version[0]);
if (version_compare($version[0], '2.2') >= 0) {
$results[0] = array('css' => 'success', 'note' => 'Version: ' . $version[0]);
}
$requiredModules = array('mod_rewrite','mod_expires');
$apacheModules = apache_get_modules();
foreach ($requiredModules as $req) {
$results[] = result($req, in_array($req, $apacheModules));
}
return $results;
}
function phpExtensions()
{
$results = array();
preg_match('/([\d]+\.[\d]+\.[\d]+)/', phpversion(), $version);
$ver = $version[0];
$results[0] = array('css' => 'danger', 'note' => 'Version: ' . $ver);
if ((version_compare($ver, '5.6.5', '>=') && version_compare($ver, '7.0.0', '<')) || version_compare($ver, '7.0.2',
'==') || version_compare($ver, '7.0.4', '==') || version_compare($ver, '7.0.6', '>=')
) {
$results[0] = array('css' => 'success', 'note' => 'Version: ' . $ver);
}
$requiredExtensions = array(
'curl',
'gd',
'intl',
'mbstring',
'mcrypt',
'openssl',
'PDO',
'SimpleXML',
'soap',
'xml',
'xsl',
'zip',
'json',
'iconv',
'Zend OPcache',
'xdebug',
);
$phpExtensions = get_loaded_extensions();
foreach ($requiredExtensions as $req) {
$results[] = result($req, in_array($req, $phpExtensions));
}
return $results;
}
function phpOptionalExtensions()
{
$optionalExtensions = array(
'imagick',
);
$phpExtensions = get_loaded_extensions();
$results = array();
foreach ($optionalExtensions as $opt) {
$results[] = result($opt, in_array($opt, $phpExtensions));
}
return $results;
}
//apacheModules();
?>
<!DOCTYPE html>
<html>
<head>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css"
integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"
integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
crossorigin="anonymous"></script>
</head>
<body>
<div class="container">
<h1>Magento 2 requirements check script</h1>
<div class="panel panel-default">
<div class="panel-heading">Apache</div>
<div class="panel-body">
<?php foreach (apacheModules() as $result): ?>
<div class="alert alert-<?php echo $result['css'] ?>" role="alert"><?php echo $result['note'] ?></div>
<?php endforeach; ?>
</div>
</div>
<div class="panel panel-default">
<div class="panel-heading">PHP</div>
<div class="panel-body">
<div role="alert" class="alert alert-warning">Loaded php.ini file: <?php echo php_ini_loaded_file()?></div>
<?php foreach (phpExtensions() as $result): ?>
<div class="alert alert-<?php echo $result['css'] ?>" role="alert"><?php echo $result['note'] ?></div>
<?php endforeach; ?>
</div>
</div>
<div class="panel panel-default">
<div class="panel-heading">Optional PHP Extension</div>
<div class="panel-body">
<?php foreach (phpOptionalExtensions() as $result): ?>
<div class="alert alert-<?php echo $result['css'] ?>" role="alert"><?php echo $result['note'] ?></div>
<?php endforeach; ?>
</div>
</div>
</div>
</body>
</html>
