Title: Invalid web server response Last modified: July 6, 2019 --- # Invalid web server response * Resolved [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/) * Hi. * I have several problems with the plugin, with WAF and also FULL WAF mode. I get many “invalid web server response” and also “error 0”. Both with web server response something. * I use LiteSpeed webserver without any problems for years now. * Any ideas how i can find what is wrong and then solve it ? * Thanks Viewing 14 replies - 1 through 14 (of 14 total) * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11706063) * Do you have any error logs (PHP and Litespeed)? * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11706068) * I have no access to Litespeed error log (shared hosting plan). As for PHP, you mean debug log ? * Also in Live log listings, i see all kind of html code … and i guess it is not normal. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11706074) * I would like to add also that Live view doesn’t work right in WAF mode (doesn’t show all the traffic), and those strange html code is showing in FULL WAF mode. * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11706510) * -Enable WP_DEBUG in your WordPress wp-config.php: Search for: `define('WP_DEBUG', false);` Replace with: `define('WP_DEBUG', true);` -Enable WordPress debug log too. Add this line below: `define( 'WP_DEBUG_LOG', true );` * The log (if any) will be located in “/wp-content/debug.log”. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11706530) * It is already like this but the log is empty (some other undefined notices not from your plugin). * Still i will leave it for a day or two. And update here. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11707521) * Here is the exact error in Live Log : * Error: The HTTP server returned the following error code: 0 Error: Cannot find your log file. Try to reload this page. * No errors in debug.log * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11709388) * Did you check in the “Firewall Log” page too? * What seems to happen is that when the Live Log sends an AJAX request to your site index.php file, your server return a “0” code, not a “200 OK”, hence the error. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11709653) * Check the Firewall log for what ? I sure can, if i know what to look for. * When Live log sends and Ajax ? The live log can work right for hours and all of a sudden i get the error and the live log becomes disabled. * Anyway, is that a problem of Live Log view ? Or that means some other problem also ? Because i don’t really care about Live log but i care if something else- not visible- is not working right. * Thanks * (also why i also get pure html code from pages sometimes ?) * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11711345) * When you get the error, check the firewall log to see if there’s anything that was written to it at that time. I don’t think you’ll find anything but it’s worth checking. * You wrote in another post that you were using CIDRAM. Did you try to disable it when using Live Log? * When enabled, Live Log sends a POST request to your index.php page every N seconds( N == “Refresh rate” option below the textarea field). The HTTP server should respond “200 OK”. You can see that from your browser “network console” (press the `F12` key). * The HTML code is likely the response body returned by your index.php page. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11711371) * Well there is NO time stamp in your Live stream when the error is logged, so i can’t compare with the error log. Maybe you should include a timestamp along with the error. * Yes, CIDRAM is completely disabled since i can’t be sure that Ninja Firewall is working right for me having also a second php script. So all the errors are without CIDRAM or anything. * I will see how this goes the next weeks. * Thanks for your prompt replies and help. * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11711392) * You can test if the firewall is working well with this: [https://webscanner.nintechnet.com/](https://webscanner.nintechnet.com/) * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11711977) * Passed the test, except ID 63000 php object injection. How do i enable this also? * Plugin Author [nintechnet](https://wordpress.org/support/users/nintechnet/) * (@nintechnet) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11714871) * In “Firewall Policies > Advanced Policies > Block serialized PHP objects in the following global variables”, enable “COOKIE”. * Thread Starter [dimal](https://wordpress.org/support/users/dimalifragis/) * (@dimalifragis) * [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11714912) * Thanks i will. And the cause was a plugin using admin-ajax for visitors. Disabling that plugin, the warning went away. Viewing 14 replies - 1 through 14 (of 14 total) The topic ‘Invalid web server response’ is closed to new replies. * ![](https://ps.w.org/ninjafirewall/assets/icon-256x256.png?rev=976137) * [NinjaFirewall (WP Edition) - Advanced Security Plugin and Firewall](https://wordpress.org/plugins/ninjafirewall/) * [Frequently Asked Questions](https://wordpress.org/plugins/ninjafirewall/#faq) * [Support Threads](https://wordpress.org/support/plugin/ninjafirewall/) * [Active Topics](https://wordpress.org/support/plugin/ninjafirewall/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/ninjafirewall/unresolved/) * [Reviews](https://wordpress.org/support/plugin/ninjafirewall/reviews/) * 14 replies * 2 participants * Last reply from: [dimal](https://wordpress.org/support/users/dimalifragis/) * Last activity: [6 years, 11 months ago](https://wordpress.org/support/topic/invalid-web-server-response/#post-11714912) * Status: resolved