I have a set of users who belong to a permission set that has read/edit access on certain custom fields on the Opportunity object. When those users attempt to modify any of these custom fields, they receive an error message stating the following:
You do not have the level of access necessary to perform the operation you requested. Please contact the owner of the record or your administrator if access is necessary.
I've looked for any validation rules that prevent these updates based on the user profile, but have found nothing that would prevent the update. What is causing this error?