Include basic plugin into functions.php to load with theme

Hi,

I’m trying to include a basic plugin into a theme build, working on Localhost I’ve simply included require_once('path/plugin.php'); ito functions.php and changed all required paths within the plugin itself and it seems to work absolutely fine. However! I dont seem to be able to install the theme on any other wordpress installation – I just get a white screen for the front and backend of the wordpress installation.

Does anyone know what I’ve done wrong here?

Many thanks in advance for any replies!!