“Your Site is Experiencing a Technical Issue”

When I try to go to the “Checkout Fields” link in the wp-admin under “WooCommerce” I get the error message “The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.” and email with the below message

Howdy!

Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.

In this case, WordPress caught an error with one of your plugins, WooCommerce.

First, visit your website (***) and check for any visible issues. Next, visit the page where the error was caught (**/wp-admin/admin.php?page=inspire_checkout_fields_settings) 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://***/wp-login.php?itsec-hb-token=manage&action=enter_recovery_mode&rm_token=***&rm_key=***

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.

Error Details
=============
An error of type E_ERROR was caused in line 96 of the file /home/***/public_html/wp-content/plugins/woocommerce/includes/data-stores/class-wc-customer-data-store-session.php. Error message: Uncaught Error: Call to a member function get() on null in /home/***/public_html/wp-content/plugins/woocommerce/includes/data-stores/class-wc-customer-data-store-session.php:96
Stack trace:
#0 /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-data-store.php(159): WC_Customer_Data_Store_Session->read(Object(WC_Customer))
#1 /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-customer.php(116): WC_Data_Store->read(Object(WC_Customer))
#2 /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-checkout.php(1179): WC_Customer->__construct(2, true)
#3 /home/***/public_html/wp-content/plugins/woocommerce-checkout-manager/includes/checkout-billing.php(72): WC_Checkout->get_value(‘billing_country’)
#4 /home/***/public_html/wp-includes/class-wp-hook.php(288): wooccm_checkout_billing_fields(Array)
#5 /home/***/public_html/wp-includes/plugin.php(208): WP_Hook->apply_filters(Array, Array)
#6 /home/***/pu

I’m using WP 5.2.1, WooCommerce 3.6.4, Flexible Checkout Fields 1.9.3 on PHP 7.1.30 with Apache.

The same issue was happening before upgrading WooCommerce and Flexible Checkout Fields just with a different stack trace see below
Howdy!
>
> Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.
>
> In this case, WordPress caught an error with one of your plugins, WooCommerce.
>
> First, visit your website (https://***.com/) and check for any visible issues. Next, visit the page where the error was caught (https://***.com/wp-admin/admin.php?page=inspire_checkout_fields_settings) 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://***.com/wp-login.php?itsec-hb-token=manage&action=enter_recovery_mode&rm_token=**&rm_key=**
>
> 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.
>
>
>
> Error Details
> =============
> An error of type E_ERROR was caused in line 1127 of the file /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-checkout.php. Error message: Uncaught Error: Call to a member function meta_exists() on null in /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-checkout.php:1127
> Stack trace:
> #0 /home/***/public_html/wp-content/plugins/woocommerce-checkout-manager/includes/checkout-billing.php(72): WC_Checkout->get_value(‘billing_country’)
> #1 /home/***/public_html/wp-includes/class-wp-hook.php(288): wooccm_checkout_billing_fields(Array)
> #2 /home/***/public_html/wp-includes/plugin.php(208): WP_Hook->apply_filters(Array, Array)
> #3 /home/***/public_html/wp-content/plugins/woocommerce/includes/class-wc-countries.php(1307): apply_filters(‘woocommerce_bil…’, Array, ‘US’)
> #4 /home/***/public_html/wp-content/plugins/flexible-checkout-fields/classes/settings.php(113): WC_Countries->get_address_fields(‘US’, ‘billing_’)
> #5 /home/***/public_html/wp-includes/class-wp-hook.php(286): Flexible_Checkout_Fields_Settings->renderInspireCheckoutFieldsSettingsPage(”)
> #6 /home/***/public_