I'm new to CiviCRM, so please bear with me. I inherited a functioning site with a CiviCRM install (on Wordpress) that was working properly. They asked me to change the domain in use, and after I attempted and failed to make that work I set everything (or at least I thought I got everything) back to how it was on the original domain. I thought everything was working fine, but now certain pages from with CiviCRM fail to load, but most work fine. I tried a bunch of different items in the header bar, but the following fail with an error 500:
Draft and Unscheduled Mailings Scheduled and Sent Mailings
I checked the http access.log file and I didn't see anything relevant other than the reported 500 error. Any idea how to diagnose and fix this?