The selected attribute System.WorkflowUserTask.Reason no longer exists

Hi colleagues,   We recently upgraded an app from 9.6.8 to 9.15.1.  But when we are attempting to upgrade it, an error displayed     in which, in generalization is pointing to this entity.  The “Reason” attribute is now disppeared on 9.15.1   but in 9.6.8, it was still there     another problem is system modules cannot be edited.   So what do we need to do in order to have a successful upgrade? Thanks much!
1 answers

Have you seen the documentation about the workflow changes:

The reason attribute is indeed deleted. You can change the your logic accordingly, either remove it if you do not need it. Or add the attribute to the workflow context entity for example.