Magento 2.3.6-p1 was a massive upgrade for the store owners that came with new features and functionalities. However, after upgrading to it, many of the store owners complained of the following error: report.ERROR: Failed to set ini option ?session.cookie_samesite? to value ?Lax? In order to solve the Failed to Set ini Option ?session.cookie_samesite? to Value ?Lax? in Magento 2.3.6-p1, the store must have the PHP 7.3 or above. If not, then set it to PHP 7.3 or above. However, if you don?t want to upgrade the PHP version, then here?s another solution. You just need to change the code in the SessionManager.php file at the vendormagentoframeworkSession.