Many sites down at the same time output buffering

What PHP and WP version are you using?

All running PHP 7.2, WP varies, from 4.9.10 to 5.1.1

This is an output buffer conflict with another plugin (or the theme). Please try to disabling and re-enabling plugins to check which one is causing the conflict. Also don’t use another caching plugin at the same time.

Is there an archive of older cache-enabler releases? Want to try reverting some of these sites to an older version to see if they are still affected. We use cache-enabler on several hundred sites and have more and more going down each week from:

PHP Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0

Unable to narrow it down to a conflict with another plugin or theme. Even have sites where there were 0 file changes within the last 48 hours and the site randomly dropped.

You can find older releases here: https://github.com/keycdn/cache-enabler/releases

Thanks, we are still facing this on many sites, almost daily we’ve been removing cache-enabler from sites. Its so random to and there is no similar situations like specific plugins or themes causing it. Could there be a issue with gzip / brotli compression being enabled on the server? Ill have to test on the next occurrence.

I don’t think it is compression related. I still think it’s a plugin or theme conflict. Please also try to complete remove the Cache Enabler and re-install it again to see if that would solve the issue.