I am working with my website host WPEngine as well to see if the error is on their end but when migrating a site from one install to another the destination site will have this error and the site and admin becomes inaccessible:

PHP Fatal error: Uncaught UnexpectedValueException: RecursiveDirectoryIterator::__construct(/nas/content/live/stghwilliams/wp-content/themes/zblocks-child/scss/): failed to open dir: Permission denied in /nas/content/live/hahnahwilliams/wp-content/plugins/wp-scss/class/class-wp-scss.php:169\nStack trace:\n#0 /nas/content/live/hahnahwilliams/wp-content/plugins/wp-scss/class/class-wp-scss.php(169): RecursiveDirectoryIterator->__construct('/nas/content/li...')\n#1 /nas/content/live/hahnahwilliams/wp-content/plugins/wp-scss/wp-scss.php(191): Wp_Scss->needs_compiling()\n#2 /nas/content/live/hahnahwilliams/wp-includes/class-wp-hook.php(292): wp_scss_needs_compiling('')\n#3 /nas/content/live/hahnahwilliams/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters(NULL, Array)\n#4 /nas/content/live/hahnahwilliams/wp-includes/plugin.php(484): WP_Hook->do_action(Array)\n#5 /nas/content/live/hahnahwilliams/wp-settings.php(582): do_action('wp_loaded')\n#6 /nas/content/live/hahnahwilliams/wp-config.php(123): require_once('/nas/content/li...')\n#7 in /nas/content/live/hahnahwilliams/wp-content/plugins/wp-scss/class/class-wp-scss.php on line 169