If you see a Error 500 - Internal Server Error when using OptimizePress, this error is actually related to your hosting setup and not specifically an error from OptimizePress.
There are a few possible causes:
1. Your web host or server is temporarily down and is not accessible, or the databases for Wordpress are not accessible
2. Your server or web host is underpowered and does not have enough resources to run Wordpress and OptimizePress
Usually these things can be fixed by first checking our minimum requirements for running OptimizePress and if you think your web host meets these requirements, get in touch with your host and ask them to look into this further as this is unfortunately not something we can fix from our side.
Didn't find an answer to your question? Contact Our Support Team (Submit a ticket)