This article will explain in detail how to add custom fields to permission sets. In order to give user permissions to read/edit custom fields, their permissions must be updated. The managed permission sets that come with the Propel package are not available for edit, so you would need to apply the changes to editable permission sets. If you are utilizing the out-of-the-box permission sets, then the two main ones you will need to edit are Propel Full Use - Custom Fields and Propel Everyone (Read Only) - Custom Fields.
1. First you will want to head to Setup.
2. In Salesforce Classic, go to Manage Users > Permission Sets. In Salesforce Lightning, go to Users > Permission Sets. (Or search for "Permission Sets" in the Quick Find search box for either)
3. Select an editable permission set like Propel Full Use - Custom Fields or Propel Everyone (Read Only) - Custom Fields
- Tip: Editable permission sets will have "Del" as an Action option
4. Go to Object Settings
5. Click name of the appropriate object where the new Custom Field was created, such as Item, Item Revision, etc.
6. Click Edit
7. Find name of the custom field in Field Permissions list and check the boxes for read and/or edit access
- Tip: Formula fields will never allow Edit access
8. Click Save