Troubleshooting
- List of Incompatible Plugins
- CloudFlare
- Nginx
- Mobile Themes
- Auto-Cache Engine
- ZenCache Pro Updater Not Working
If you're having issues running ZenCache, a great first step is to verify that you're not running any of these plugins, which have been known to cause problems:
-
Force Gzip - Force Gzip uses
ob_gzhandler(), which ZenCache is not compatible with. ZenCache is not compatible with output buffers that attempt to pre-compress HTML output. -
CSS-JS-Booster - CSS-JS-Booster uses
ob_gzhandler(), which ZenCache is not compatible with. ZenCache is not compatible with output buffers that attempt to pre-compress HTML output. - Mobble - Mobble provides conditional functions for detecting a variety of mobile devices & tablets. However, since ZenCache generates caches using PHP Output Buffering, once a cache is generates no PHP functions on that page will be evaluated until the cache is regenerated. If you must use Mobble, you can exclude mobile User-Agents from being cached by ZenCache (see Mobile Themes).
- Plainview Activity Monitor - We have had reports of this plugin possibly causing issues with the cache clearing every time the WordPress Dashboard is accessed. See this issue for more details.
If you're using CloudFlare with ZenCache, keep in mind that if you have Auto Minify (HTML) turned on in CloudFlare, all of the HTML comments will be stripped from your content. The ZenCache notes that get added to the HTML to tell you that ZenCache is working properly (see Dashboard -> ZenCache -> Enable/Disable -> How Can I Tell ZenCache is Working?) are written to the HTML as HTML comments, so CloudFlare will strip those as well.
This might make it seem like ZenCache isn't running when in fact it is.
To see if ZenCache is running properly, you can temporarily put CloudFlare into Development Mode, which disables this Auto Minify functionality and allows you to see the ZenCache notes in the HTML.
With CloudFlare's Auto Minify (HTML) turned on, you might also see 4 blank lines at the very bottom of your source code where you'd expect to find the ZenCache notes:
ZenCache and ZenCache Pro both support the Nginx web server. If you're having issues, here are a few things to try:
- If you have Zlib compression enabled, try disabling it.
If you're having issues with your Mobile Theme appearing on the Desktop, or the Desktop Theme appearing on mobile devices, ZenCache is probably caching your mobile theme and then showing it to all visitors, including your Desktop visitors. To prevent this from happening, you'll need to tell ZenCache to disable caching for mobile devices.
With ZenCache Pro, you can specify a list of User-Agent Exclusion Patterns in Dashboard → ZenCache → User-Agent Exclusion Patterns:
iPhone * Mobile
iPod * Mobile
Android * Mobile
BB * Mobile Safari
BlackBerry * Mobile Safari
IEMobile/10.0 * Touch
IEMobile/7.0
IEMobile/9.0
webOS
For more information about this feature, see the Plugin Options Documentation.
When enabled, the Auto-Cache Engine runs every 15 minutes via WP Cron. If the Auto-Cache Engine doesn't seem to be working, you can try manually initiating it by visiting http://yoursite.com/?zencache__auto_cache_cron=yes.
If you're getting a 404 error when attempting to run the ZenCache Pro Updater, you most likely have software on your server blocking the request to the WebSharks update server. The most common culprit is Apache's ModSecurity module.
Please contact your web host with the following request, which should disable the particular ModSecurity rule that often causes issues with the ZenCache Pro Updater:
I run a WordPress plugin called ZenCache Pro and its updater requires that ModSecurity rule #340163 be whitelisted/disabled for my domain. Can you please whitelist/disable ModSecurity rule #340163?