Error 500 after migration from Easy Apache 3 to EA4 on Centos6 VPS

I made the mistake of clicking the button in WHM to migrate from Easy Apache 3 to EA4 and now I am getting a 500 error when I try to visit my site. What have I broken and how can I solve the problem? I've tried restarting httpd and restarting the server. I've checked the .htaccess file and it's still in place. I'm using Apache 2.4 on a Centos6 server platform.