Users are getting below error message in modern UI when they try to update any field locked by process. This message doesn't show the field name rather the field ID.
CMN-0015: Attribute 'lm_team_role' was locked and cannot be changed.
Release : 15.8
Component : CA PPM BUSINESS PROCESS MANAGEMENT
This message is as currently designed. User knows which field they try to update so that ID they see is really irrelevant to them. With that in mind we actually introduced a feature in 15.9.1 where users will now see a lock sign next to the attribute any time it is locked by the process, this change for now only for the Properties and Details Flyout and grid will still be reactive for now.