Hello @rom1our
I’ve tested the Twenty Fourteen theme with custom sidebars and can’t replicate it.
Usually that errors come from Cache/Memory plugins, but other plugins have possibilities too. Please try the following steps to troubleshoot this issue.
Deactivate all the plugins and live only the Custom Sidebars active. If everything is well, activate one plugin at a time to find the plugin that causing it.
Let me know how it went!
Kind regards,
Nastia
Hi Nastia,
thank you for the fast reply. I’ve deactivated all the plugins beside
Child Theme Configurator Version 2.2.4.1
which I use to check the theme is properly working.
Activating Custom sidebars I received from Child Theme Configurator the same result as before:
Notice: Undefined index: cs-1 in /web/htdocs/www.tourist-in-rom.com/home/wp-content/plugins/custom-sidebars/inc/class-custom-sidebars-replacer.php on line 147
I’m really sorry because I’ve seen configuration of the custom sidebars plugin is very comfortable.
With kind regards
Bernhard
Thank you for the follow-up! Can you please export your sidebars and email the configuration to us so we can try and reproduce?
If you don’t want to share your URL here you can send it to us directly by using our contact form:
https://premium.wpmudev.org/contact/#i-have-a-different-question
Send in:
Subject: “Attn: Joshua Dailey”
– Link to your WordPress site
– The sidebar file
– Link back to this thread for reference
– Any other relevant urls

Dear @rom1our,
Could you add a list of active plugins?
Marcin
Hi Marcin,
Accordions
Akismet Anti-Spam
BackWPup
Child Theme Configurator
Content Blocks
Custom Menu Wizard
Duplicate Page
Enhanced Text Widget
EU Coolie Law
f(x) Editor
Flexible Posts Widget
Fourteen Colors
Google Adsense
Google Analytics for WordPress
Google Maps WD
Head and Footer Scripts Inserter
Last Modified Timestamp
Lingotek Translation
Nextgen Gallery
Open external links in a new window
Page scroll to id
Polylang
Popup Maker
Post Date Time Change
Recent Posts Widget With Thumbnails
Redirection
Simple Custom CSS
Slicknav Mobile Menu
Weather Underground
WP Fastest Cache
WP Lightbox 2
Yoast SEO
Youtube
BR
B
@rom1our it appears to be a conflict with the theme or one of the plugins. Unfortunately, we are unable to replicate the issue. 🙁
Is it possible to try without the child theme active on a test site? Let us know if it works on a basic theme setup.
Thank you for using Custom Sidebars. I am going to mark this topic resolved because we haven’t heard from you in awhile. If you tested and the issue was unresolved we can reopen the ticket. Thank you.