@ custom

[diybrewing]

When I hit save on my configuration and bundle products, it will then go to a 404 page and in the address bar go to link @custom. We are now on a base 2.3 setup with no third party apps installed. The logs are not helpful. Does anyone have any clues?

[diybrewing]

Here is my exception log

Unable to unserialize value. {"exception":"[object] (InvalidArgumentException(code: 0): Unable to unserialize value. at /home/diybrewi/public_html/vendor/magento/framework/Serialize/Serializer/Json.php:39)"} 

[Manthan Dave]

@diybrewing - AKAIK this serialize issue is known issue , Refer below link for its solution.

Here is the link - https://community.magento.com/t5/Magento-2-x-Version-Upgrades/Upgrade-to-Magento-2-2-1-Unable-to-uns...

Reference link - https://magento.stackexchange.com/questions/194010/magento-2-2-unable-to-unserialize-value