Posting on Behalf of a Customer.
It is found that given a rule in NXT loading to an SFDC Object, if a field on the target object has been deleted, permissions error gets thrown in logs, but user is unable to make further changes to rule actions as it never loads ( In cases where you want to remove this field from the action to fix).
In some places of our product, I believe if a target field is deleting the mapping goes blank (prob also gives notice) , which you can still update to remove it. If we don’t have this, it be great to give this ability to rules, it would allow admins to tackle this without having to go to Gainsight Support.
