Title: Permalink Weird Issue
Last modified: August 19, 2016

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# Permalink Weird Issue

 *  [board07734](https://wordpress.org/support/users/board07734/)
 * (@board07734)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/permalink-weird-issue/)
 * I upgraded to 3.0 yesterday and got a repeating error:
    Warning: preg_match()[
   function.preg-match]: Unknown modifier ‘0’ in /****/wp-includes/classes.php on
   line 210
 * Warning: preg_match() [function.preg-match]: Unknown modifier ‘0’ in /****/wp-
   includes/classes.php on line 211
 * The fix was to go into the Permalink Settings and set it to Default then back
   to my setting. The problem is if I just go into the Permalink Settings (even 
   before touching anything) the error comes back and I have to set it to Default
   and back again to fix it. Any thoughts?

Viewing 3 replies - 1 through 3 (of 3 total)

 *  [esmi](https://wordpress.org/support/users/esmi/)
 * (@esmi)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/permalink-weird-issue/#post-1601923)
 * Have you tried:
 * – deactivating **all** plugins to see if this resolves the problem? If this works,
   re-activate the plugins one by one until you find the problematic plugin(s).
 * – switching to the default theme to rule out any theme-specific problems?
 *  Thread Starter [board07734](https://wordpress.org/support/users/board07734/)
 * (@board07734)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/permalink-weird-issue/#post-1601950)
 * Thanks for the reply, I just tried those and the problem persisted. Anything 
   else I could try?
 *  [esmi](https://wordpress.org/support/users/esmi/)
 * (@esmi)
 * [15 years, 10 months ago](https://wordpress.org/support/topic/permalink-weird-issue/#post-1602057)
 * You could try:
 * – [resetting the plugins folder](http://codex.wordpress.org/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F)
   by FTP or phpMyAdmin. Sometimes, an apparently inactive plugin can still cause
   problems.
 * – re-uploading the wp-admin and wp-includes folders from a **fresh** download
   of WordPress in case you have a damaged file.

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Permalink Weird Issue’ is closed to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 3 replies
 * 2 participants
 * Last reply from: [esmi](https://wordpress.org/support/users/esmi/)
 * Last activity: [15 years, 10 months ago](https://wordpress.org/support/topic/permalink-weird-issue/#post-1602057)
 * Status: not resolved

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