I am using Automattic AMP plugin along with Accelerated Mobile Pages https://ampforwp.com . Thanks for your suggestion. Next time, I will check debug log to find out cause of problem.
This reply was modified 7 years, 7 months ago by stgizmo.
I got same problem. My Feed burner has stop updating after upgrade to v.1.5. Due to this, I uninstalled WP Super Cache and re-install again. The problem has been solved.
This reply was modified 7 years, 8 months ago by stgizmo.