Cannot save setting changes

Whenever I click “submit” after changing settings, the page reloads and reverts to the previous setting. I haven’t attempted to change the settings in so long that I have no idea when this issue began. Based on previous topics, I’m guessing it’s likely a plugin compatibility issue. Unfortunately, we use a lot of plugins, and I’d prefer not to list them all here. Is there any other way to narrow it down? Or should I just list all my active plugins for you?

The page I need help with: [log in to see the link]