Troubleshooting
Run your test with Chrome or Firefox (last version). Empty your browser cache.
a) Check if you have the PHP version equal or bigger than 7.0.
b) Check your database and tables. You can use the PHPmyAdmin or similar tool.
c) Look at your error_log file for errors.
d) Check your PHP memory Limit.
PHP memory_limit is per-script. For example, although PHP’s memory limit may be set high to 1GB, that does not mean that scripts will pile up to use that 1GB. This helps prevent poorly written scripts for eating up all available memory on a server… Then, I guess 256M is a good number for PHP ini.
You can find this info with the function PHPinfo().
If you have questions about those points above, request support to your hosting company.