I have tried installing in a subdomain and in a directory.

I have tried to activate  PDO in php.ini:

extension=pdo.soextension=pdo_sqlite.soextension=sqlite.soextension=pdo_mysql.so

Running PHP 5.5
ASO customer service tells me PDO is active on my sites.

I'm just clever enough to be dangerous, but don't know what to try next. I have a feeling that the problem is with my hosting service, but was hoping someone here could help me understand better what I need to be asking.

Oh, one more thing. When I try to install using Installatron, I get the following message, which leads me to think I'm still having issues with PDO, which frankly, I am not familiar with.
Select the version of Oxwall to install.Version1.8.3 (requirements not met) (recommended)1.8.1 (requirements not met)1.8.0 (requirements not met)1.7.5 (requirements not met)1.7.4 (requirements not met)1.7.3 (requirements not met)1.7.2 (requirements not met)1.7.1 (requirements not met)1.7.0 (requirements not met)1.6.0 (requirements not met)1.5.3 (requirements not met)1.5.2 (requirements not met)1.5.1 (requirements not met)1.5.0 (requirements not met)1.4.1 (requirements not met)1.4.0 (requirements not met)1.3.2 (requirements not met)1.3.1 (requirements not met)1.3 (requirements not met)1.2.6 (requirements not met)! The selected version 1.8.3 is not compatible with the selected install location.

Requirements:
php-pdo-mysql-version-minimum v1 (detected: OFF)
Thanks in advance for your patience and any help you can offer.