Problem when trying to load the customizer

Hello,

When I want to go on the customizer, I have the message “There was a problem when trying to load the customizer”. The sources of this problem listed in the article https://docs.presscustomizr.com/article/285-there-was-a-problem-when-trying-to-load-the-customizer don’t concern me except maybe for the conflict of plugins with the theme. I have actually these plugins :

– 1&1 WP Wizard (version 2.1.0)
– BackUpWordPress (version 3.6.4)
– Broken Link Checker (version 1.11.5)
– EWWW Image Optimizer (version 4.1.0)
– Google Analytics for WordPress by MonsterInsights (version 7.0.1)
– Hueman Addons (version 2.0.16)
– Jetpack by WordPress.com (version 5.8)
– MailChimp (version 1.5.7)
– Redirection (version 3.2)
– W3 Total Cache (version 0.9.6)
– Yoast SEO (version 6.3.1)

Can somebody tell me if one of these plugins is the problem, or where can be the problem ?

All informations about my website :

# SITE_URL: http://www.subinfo.fr
# HOME_URL: http://www.subinfo.fr
# IS MULTISITE : No
# THEME | VERSION : Hueman | v3.3.27
# WP VERSION : 4.9.4
# PERMALINK STRUCTURE : /%year%/%monthnum%/%day%/%postname%/
# PHP Version: 5.6.33
# MySQL Version: 5.5.59-0+deb7u1-log
# Web Server Info: Apache
# WordPress Memory Limit: 40MB
# PHP Memory Limit: 256M
# PHP Upload Max Size: 67108864
# PHP Post Max Size: 67108864
# PHP Upload Max Filesize:67108864
# PHP Time Limit: 0
# PHP Max Input Vars: 1000
# PHP Arg Separator: &
# PHP Allow URL File Open:Yes
# WP_DEBUG: Disabled
# Show On Front: page
# Page On Front: Accueil(#97)
# Page For Posts: Tous les articles(#8)

Thank you very much !