Hi all,
I’ve installed GetGrav in a subdirectory by uploading the unzipped files. Whenever I go to http://mydomain.com/gravsub it always displays
Whoops \ Exception \ ErrorException (E_CORE_WARNING)
Module ‘PDO’ already loaded
When I reload it, everything is fine and I could open all pages. But when I close the browser and come back later it again shows this error message. So the problem is repeatable.
Any ideas?
Can you paste a screenshot of your actual whoops error?
From a quick Google of your error, it looks like maybe you switched from an older PHP to PHP 5.4? And perhaps you have a php.ini file from that older version of PHP that is manually loading the pdo.so module.
Grav doesn’t even use PDO, and this is purely a PHP setup error. I suggest finding your php.ini file and commenting out the PDO modular installation line and then restart apache.
For reference:
http://250kb.de/u/150127/p/eIzwHbwPu7yM.png
Unfortunately it’s a simple webhosting which I use. I could not migrate PHP on my own, nor do I have access to my php.ini 
You will need to contact your hosting provider then. This is a PHP error that will show up no matter what PHP script you use, this isn’t related to Grav at all.
Strange, because it does not appear when using e.g. Wordpress…
I think that WordPress is suppressing the warnings, not that the warnings are not happening in WordPress.
Might be, yes. But it seems that the problem is also solved now: In my admin interface I have a “PHP Switcher”. Currently 5.4.36 was selected, now I changed it to 5.6.4 and it the error did not appear anymore 
Many thanks for your support!
Ah good, PHP 5.6.4 is a better option going forward anyway