The error was caused by Sumo Subscription Plugin. I have forwarded the error report to the developers for review. I attach the error report for your information:
In this case, WordPress caught an error with one of your plugins, SUMO
Subscriptions.
First, visit your website (https://knpayrollplus.com/) and check for
any visible issues. Next, visit the page where the error was caught
(https://knpayrollplus.com/wp-admin/admin.php?page=oxi-accordions-style-view&styleid=1)
and check for any visible issues.
Please contact your host for assistance with investigating this issue further.
If your site appears broken and you can't access your dashboard
normally, WordPress now has a special "recovery mode". This lets you
safely login to your dashboard and investigate further.
https://knpayrollplus.com/login-page/?action=enter_recovery_mode&rm_token=wW0OkLxJAEifL5Arjp7NvU&rm_key=iMnThWkYxA6khRxPGiEfdK
To keep your site safe, this link will expire in 1 day. Don't worry
about that, though: a new link will be emailed to you if the error
occurs again after it expires.
When seeking help with this issue, you may be asked for some of the
following information:
WordPress version 6.1.1
Active theme: Thrive Theme Builder (version 3.14.3)
Current plugin: SUMO Subscriptions (version 14.5)
PHP version 7.4.33
Error Details
=============
An error of type E_ERROR was caused in line 222 of the file
/home/knpaufcz/public_html/wp-content/plugins/sumosubscriptions/includes/class-sumosubs-enqueues.php.
Error message: Uncaught Error: Class 'SUMOSubs_Variation_Data' not
found in /home/knpaufcz/public_html/wp-content/plugins/sumosubscriptions/includes/class-sumosubs-enqueues.php:222
Stack trace:
#0 /home/knpaufcz/public_html/wp-includes/class-wp-hook.php(308):
SUMOSubs_Enqueues::frontend_script('')
#1 /home/knpaufcz/public_html/wp-includes/class-wp-hook.php(332):
WP_Hook->apply_filters(NULL, Array)
#2 /home/knpaufcz/public_html/wp-includes/plugin.php(517):
WP_Hook->do_action(Array)
#3 /home/knpaufcz/public_html/wp-includes/script-loader.php(2180):
do_action('wp_enqueue_scri...')
#4 /home/knpaufcz/public_html/wp-includes/class-wp-hook.php(308):
wp_enqueue_scripts('')
#5 /home/knpaufcz/public_html/wp-includes/class-wp-hook.php(332):
WP_Hook->apply_filters(NULL, Array)
#6 /home/knpaufcz/public_html/wp-includes/plugin.php(517):
WP_Hook->do_action(Array)
#7 /home/knpaufcz/public_html/wp-includes/general-template.php(3043):
do_action('wp_head')
#8 /home/knpaufcz/public_html/wp-content/plugins/accordions-or-faqs/Includes/Frontend.p