I’m installing a fresh Omeka S 2.0 on an RHEL server. When I navigate to mysite.com I’m forwarded to mysite.com/install, the page is blank, but examination reveals a 500 error. There are no errors in the PHP or MySQL logs
Changing ‘install’ to anything else (including index.php) shows Omeka’s Page not Found.
I’ve verified that MySQL is installed and correctly configured, and that mods rewrite is working as intended. A test page that echoes phpinfo() works as intended.
Any reason why you’re using version 2.0 instead of a newer one?
You can try the instructions on enabling error display. Also, a “white screen” error like this typically is going to be logged somewhere, in the logs for PHP or Apache typically.
Version 2 was chosen for compatibility with some modules we have been using.
There was nothing in the Apache log, but the PHP error was
Interface ‘JsonSerializable’ not found in /var/www/html/application/src/Stdlib/Message.php on line 4
I ran yum install php-json and all was good. Apparently, RHEL doesn’t include PHP support for JSON out of the box.