Title: [Plugin: HTTP 404 Email Notifier] error Last modified: August 20, 2016 --- # [Plugin: HTTP 404 Email Notifier] error * Resolved [dpthakar](https://wordpress.org/support/users/dpthakar/) * (@dpthakar) * [14 years ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/) * I got following error when enabled on my blog [linuxreaders.com](http://linuxreaders.com/) * Warning: preg_grep() [function.preg-grep]: Unknown modifier ‘/’ in /home/dpthakar/ public_html/wp-content/plugins/http-404-email-notifier/http-404-email-notifier. php on line 30 * [http://wordpress.org/extend/plugins/http-404-email-notifier/](http://wordpress.org/extend/plugins/http-404-email-notifier/) Viewing 6 replies - 1 through 6 (of 6 total) * Plugin Author [Carl](https://wordpress.org/support/users/carlthome/) * (@carlthome) * [14 years ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760263) * Thanks for telling me. The issue has been fixed in version 0.6. * [Drachsi](https://wordpress.org/support/users/drachsi/) * (@drachsi) * [13 years, 11 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760336) * Hi, * I just installed the 404 email into version 3.4 WordPress and find it does not send an email, any ideas? * Regards * Drachsi * [neckrub](https://wordpress.org/support/users/neckrub/) * (@neckrub) * [13 years, 3 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760452) * Even though I had installed HTTP 404 Email Notifier version 0.6, activated it, deactivated it, and deleted the files (from the Dashboard and in the “Plugins” directory via FTP), I get this warning when loading my home page ([http://yournetsuccess.com](http://yournetsuccess.com)):“ Warning: preg_grep() [function.preg-grep]: Unknown modifier ‘/’ in /home/neckrub/ public_html/content/wp-content/plugins/http-404-email-notifier/http-404-email- notifier.php on line 30” * If you can, would you please advise me how I could fix this. * PS: I’m using WP Version 3.5.1 * Thank you. * [neckrub](https://wordpress.org/support/users/neckrub/) * (@neckrub) * [13 years, 3 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760453) * Here’s how I resolved the issue described in my previous post about “HTTP 404 Email Notifier” WP Plugin: Before anything else, I deactivated and deleted “ HTTP 404 Email Notifier” WP Plugin, then checked via FTP that the plugin’s directory was no longer in my site’s “Plugins” directory. * Next: * 1) Logged out of WP Dashboard and loaded site 2) Viewed source code of “Home” page on which warning was displaying 2a) Note: Warning does not display when logged in as admin 3) At bottom of source code page, the time stamp showed the same time stamp: “Served from: yournetsuccess.com @ 2012-04-15 15:21:29 –>” no matter how many times I reloaded the page 4) Actual day was: 2013-02-04 5) Also noticed a reference above the time stamp to the “W3 Total Cache” plugin, which I had previously installed and subsequently deleted. 6) “W3 Total Cache” appears to have left some artifacts on my server causing a conflict with “HTTP 404 Email Notifier” generating the warning even though “HTTP 404 Email Notifier” WP Plugin” was already deleted. 7) Logged in and reinstalled “W3 Total Cache” 8) Logged out and loaded “Home” page: Warning no longer appears 9) Logged in and deactivated“ W3 Total Cache” 10) Logged out and loaded “Home” page: Warning still not appearing 11) Logged in and deleted “W3 Total Cache” as well as its files 12) Logged out and loaded “Home” page: Warning still not appearing * I’m concluding that the original warning was the result of a conflict between the 2 plugins, and it is now resolved. * PS: References to “W3 Total Cache” and time stamp no longer appear on “Home” page source code. * Plugin Author [Carl](https://wordpress.org/support/users/carlthome/) * (@carlthome) * [13 years, 3 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760454) * I’m glad you’ve managed to solve the issue by yourself. * This plugin is no longer maintained and was therefore removed from the WordPress repository last year. Unfortunately it is still available in the plugin directory and I’ve contacted WordPress in order to resolve this. * Sorry for the inconvenience. * [neckrub](https://wordpress.org/support/users/neckrub/) * (@neckrub) * [13 years, 3 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760458) * Thanks, Carl. I didn’t know the plugin was no longer being supported. Much obliged for your follow-up! Best to you! Phil Viewing 6 replies - 1 through 6 (of 6 total) The topic ‘[Plugin: HTTP 404 Email Notifier] error’ is closed to new replies. * ![](https://s.w.org/plugins/geopattern-icon/http-404-email-notifier.svg) * [HTTP 404 Email Notifier](https://wordpress.org/plugins/http-404-email-notifier/) * [Support Threads](https://wordpress.org/support/plugin/http-404-email-notifier/) * [Active Topics](https://wordpress.org/support/plugin/http-404-email-notifier/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/http-404-email-notifier/unresolved/) * [Reviews](https://wordpress.org/support/plugin/http-404-email-notifier/reviews/) * 6 replies * 4 participants * Last reply from: [neckrub](https://wordpress.org/support/users/neckrub/) * Last activity: [13 years, 3 months ago](https://wordpress.org/support/topic/plugin-http-404-email-notifier-error/#post-2760458) * Status: resolved