Title: ‘Activate Compatibility Mode’ not working
Last modified: August 28, 2019

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# ‘Activate Compatibility Mode’ not working

 *  Resolved [nealhulme](https://wordpress.org/support/users/nealhulme/)
 * (@nealhulme)
 * [6 years, 9 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/)
 * I’m currently developing a site using the Semplice Theme but when I have tried
   to follow their instructions to set a custom 404 using the 404page I have been
   unable to. The problem seems to be saving the ‘Activate Compatibility Mode’ setting.
   When I toggle it on and save the settings it returns to the off position. I tried
   the same thing using the ‘Twenty Nineteen’ template and experienced the same 
   thing.
 * I know enough about databases to be dangerous so I looked at the values in the
   MySQL database and found the 404page_settings row and manually changed the ‘STD’
   to ‘CMP’ and now the plugin works fine. If I try setting the values again the‘
   Activate Compatibility Mode’ will toggle off but not back on again.
 * Everything is up to date and the only plugins/templates I currently have installed
   are the Semplice Template, Cookie Notice, WPForms Lite and Maintenance along 
   with 404page.

Viewing 4 replies - 1 through 4 (of 4 total)

 *  [barbara1988](https://wordpress.org/support/users/barbara1988/)
 * (@barbara1988)
 * [6 years, 9 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/#post-11875566)
 * Hi,
 * I have the same probleme and the only plugin we have in common is WPForms.
 * Maybe we should check the compatibility between those 2 plugins.
 *  Thread Starter [nealhulme](https://wordpress.org/support/users/nealhulme/)
 * (@nealhulme)
 * [6 years, 9 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/#post-11875616)
 * I’ve just uninstalled WPForms and the issue is still there so it doesn’t seem
   to be a conflict there.
 * I also have a problem where the selected page is being hidden from Semplice even
   though I have the ‘Hide the selected page from the Pages list’ deselected. In
   the interim I can deactivate the plugin or edit the querystring for the template’s
   editing window if I need to make any edits.
 *  Plugin Contributor [Peter Raschendorfer](https://wordpress.org/support/users/petersplugins/)
 * (@petersplugins)
 * [6 years, 9 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/#post-11884695)
 * Sorry, I made an error that I didn’t notice in my tests. Should be fixed with
   version 11.0.2. Please update and let me know if everything works fine.
 * Regards,
    Peter
 *  Plugin Contributor [Peter Raschendorfer](https://wordpress.org/support/users/petersplugins/)
 * (@petersplugins)
 * [6 years, 8 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/#post-12000336)
 * No response since 1 month, but other users confirmed, that it works in 10.0.2,
   marked as resolved

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘‘Activate Compatibility Mode’ not working’ is closed to new replies.

 * ![](https://ps.w.org/404page/assets/icon-256x256.png?rev=3345344)
 * [Smart Custom 404 Error Page](https://wordpress.org/plugins/404page/)
 * [Support Threads](https://wordpress.org/support/plugin/404page/)
 * [Active Topics](https://wordpress.org/support/plugin/404page/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/404page/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/404page/reviews/)

 * 4 replies
 * 3 participants
 * Last reply from: [Peter Raschendorfer](https://wordpress.org/support/users/petersplugins/)
 * Last activity: [6 years, 8 months ago](https://wordpress.org/support/topic/activate-compatibility-mode-not-working/#post-12000336)
 * Status: resolved