The issue can occur when a gift query is included in the mailing, and it's being sorted by query under Format > Sort
In the meantime, the following can help resolve this error until the issue is resolved:
- Instead of including a static gift query, include:
- Constituent query (or another query type)
- Dynamic gift query (may not resolve for all mailings)
- Instead of sorting by Query order, sort the mail job Alphabetically or choose Do not sort.
- Note: The Query field must be removed from the Sort Fields pane even if sorting is turned off or Alphabetical is added