More Major Critical Errors with Woo 8.5.1 and 8.5.

We are having the same issue – critical error when trying to view cart or checkout with the new releases 8.5 and 8.5.1. When we roll back to V8.4 all works fine.

We are unable to checkout for guest users. When we roll back the update everything work fine.

Could this be a plugin conflict? We experience the same error, it seems to be caused by the Flexible Checkout Fields plugin. A rollback to 8.4 fixes the error. I can share logs if needed.

This happened yesterday and I rolled back to 8.4 and things are fine. Got a message saying the bug in 8.5 was fixed in 8.5.1, but that version also has some bug and is the version that introduced the issues on my site.

I updated Flexible Checkout Fields to 3.6.0 and then it worked again.

https://developer.woo.com/2024/01/16/woocommerce-8-5-1-issues-with-web-application-firewalls-modsecurity/

they are aware of this issue,

For me it was not a 403, but a 500 critical error when entering the basket or payout process.

Many thanks @sureshramasamy many thanks!

Option 3 below has done the trick for me. I have no need to enable the option anyway, surely it should be disabled by default?

What action should I take?

• Plesk already has a help article targeting this issue, identifying Comodo rule with ID 218500 being false-positively triggered when Woocommerce 8.5 is in use. They recommend disabling the rule following the steps on their page.
• Check with your host to see if ModSecurity is enabled. If that is the case, you may ask your host to adjust the firewall rules to allow the cookies set by Woo’s Order Attribution feature. You can find more information about the cookies used by this feature in our documentation.
• If the above doesn’t work for you, disable the Order Attribution feature to prevent future users from seeing the 403 errors by going to WooCommerce > Settings > Advanced > Features and toggling the Order Attribution feature off.