Error after an attempt to modify a Standard Field using Application Composer

Summary

Error after an attempt to modify a Standard Field using Application Composer

Content

Hi,

We tried changing the "Updatable" property of the Standard Field "Problem Description" in the Service request page using Application Composer.

The EL Expresession used for this customization is QueueId == null ;
The Idea for the EL Expression is to make the "Problem Description" field (Service Request Details) updatable only till the SR is Auto assigned to a Queue as per the Assignment Rules.

The Sandbox was published and we got the below error while creating the Service Request as an employee in the SR Creation Page.