Unable to save entity Adobe Commerce backend

This article provides a solution for when you are unable to save an entity in the Adobe Commerce backend. For example, when you cannot edit and save a specific cart_price rule.

Affected products and versions

This issue can affect all Adobe Commerce versions which have Max Session Size configured. This was added starting from Magento Open Source 2.3.7-p1 and Adobe commerce (all deployment methods) 2.4.3.

Issue

When you try to reconfigure your store the page reloads and your changes are not saved. A message can be seen in var/log/system.log:

[2021-11-27 00:30:52] report.WARNING: Session size of 418056 exceeded allowed session max size of 256000. [] []

Steps to reproduce:

An example of store configuration not being saved:

1. Select a rule in the Adobe Commerce store in Production > Marketing > Cart price rules.
2. Choose a rule and set to Inactive and save the change.

Expected result:

The rule is set to inactive.

Actual result:

• Page reloads without any message.
• The rule is still set to active.

Cause

This issue is related to new functionality introduced recently that has impacted the Max Session Size. See Session management in our developer documentation.

Solution

Increase the “Max Session Size” value in (Stores > Configuration > Advanced > System > Security > Max Session Size).

Related reading

• Marketing Menu in our user guide.