Title: Page Caching Last modified: March 1, 2020 --- # Page Caching * Resolved [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/) * Dear sir, madam, I am trying to use page caching of Hummingbird. Though clicking the activate button does not change anything. I double checked the wordpress debugging mode, but nothing is shown. I am using an NGINX server. Which actions should I undertake to make sure that I can use this feature? * Cheers, Stefaan * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fpage-caching-4%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 12 replies - 1 through 12 (of 12 total) * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12496930) * [@ssaghijs](https://wordpress.org/support/users/ssaghijs/), * Could you please the browser console for errors during activation? Just to make sure that I understood you correctly – once you click on “Activate” nothing happens? Or does it activate page caching on the plugin side, but nothing is cached on the front-end? * Best regards, Anton * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12498650) * Dear Anton, you understood me well indeed. Once I click “Activate” nothing happens? No other page is activated which allows me to enable caching. Cheers, Stefaan PS I will check the browser console. Are there other things which I equally can check? * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12500683) * [@ssaghijs](https://wordpress.org/support/users/ssaghijs/), * Browser console errors are the easiest. The next step would be to enable debugging and check the debug.log for errors. * I’ve seen similar errors a while back on one site, it was related to strict server caching. And purging the server cache did help. * Best regards, Anton * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12504131) * It gives some warnings but no errors including the debug.log, any next steps? Cheers, Stefaan * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12504173) * Tried to purge cache on Nginx server also, no luck either. * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12505406) * If there are no errors – it means Hummingbird is working fine. Look for conflicts– could be there’s another plugin that’s already doing something similar, your host may be blocking Hummingbird. Also, as I said in my previous post, disabling server/hosting cache is a good way to test if that’s the cause of issues. If you have directory permission issues, it might prevent page cache from working properly. But most of those issues are covered by Hummingbird and you should see a notice if something is not working as expected. * Best regards, Anton * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12508605) * Tx, could it be that these debug warnings are the issue: session_start(): Cannot send session cookie – headers already sent in …custom.php on line 282 [04-Mar- 2020 16:56:06 UTC] PHP Warning: session_start(): Cannot send session cache limiter– headers already sent in …custom.php on line 282 * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12509864) * That ‘…custom.php’ file is interfering, which might indicate an issue. Could you please try disabling the plugin with that file and see if that helps? Or post here what’s on line 282 in that file. * Best regards, Anton * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12513008) * It is in the lib file of the theme. The following code is there: * 278 function enable_session() 279 280 { 281 if (!isset ($_SESSION)) { 282 session_start(); 283 } 284 } * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12514118) * What is the theme? I will try to test it on my end * Thread Starter [ssaghijs](https://wordpress.org/support/users/ssaghijs/) * (@ssaghijs) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12514860) * It is a theme which is developed on our own. Can I provide you with other info? * Cheers, Stefaan * [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * (@vanyukov) * [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12525816) * [@ssaghijs](https://wordpress.org/support/users/ssaghijs/), * The only other thing I can offer is try to replicate this on my local setup and see if it’s possible to fix. I would need your theme for that. Please use the contact form [https://premium.wpmudev.org/contact/](https://premium.wpmudev.org/contact/). Select “I have a different question”, use “Attn: Anton” as your subject. * Best regards, Anton Viewing 12 replies - 1 through 12 (of 12 total) The topic ‘Page Caching’ is closed to new replies. * ![](https://ps.w.org/hummingbird-performance/assets/icon-256x256.gif?rev=2633221) * [Hummingbird Performance - Cache & Page Speed Optimization for Core Web Vitals | Critical CSS | Minify CSS | Defer CSS Javascript | CDN](https://wordpress.org/plugins/hummingbird-performance/) * [Frequently Asked Questions](https://wordpress.org/plugins/hummingbird-performance/#faq) * [Support Threads](https://wordpress.org/support/plugin/hummingbird-performance/) * [Active Topics](https://wordpress.org/support/plugin/hummingbird-performance/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/hummingbird-performance/unresolved/) * [Reviews](https://wordpress.org/support/plugin/hummingbird-performance/reviews/) ## Tags * [page caching](https://wordpress.org/support/topic-tag/page-caching/) * 12 replies * 2 participants * Last reply from: [Anton Vanyukov](https://wordpress.org/support/users/vanyukov/) * Last activity: [6 years, 2 months ago](https://wordpress.org/support/topic/page-caching-4/#post-12525816) * Status: resolved