You have created an extension field with list values in Visits > Attendees but the field is greyed out when you try to edit it.
Reproducing the Issue
1. Go to the Visits workcenter.
2. Go to the Visits view.
3. Go to the Attendees facet.
4. In the attendees table, you have added an extension field of type List.
5. Click Edit and try to edit the field.
Result: The field is greyed out and cannot be edited.
With the 1708 release, we have enabled stable anchors for the Attendees table and the extension field flow from the business partner (account, employee and contact) to Attendees in Visits and other activities. This means you can now add extension fields from Accounts, Contact and Employee into the Contacts/Attendees/Other Parties tables for Visits.
However, the Edit function is not yet supported.
This functionality has been added to our product backlog, to be considered for a future release.
KBA , SRD-CC , Cross Components , Bug Filed