New in version 4.0 is a bug that causes all filters that search based on a Fix Version or Affects Version to be broken after the related version is renamed. This means that it is now, from a practical standpoint, impossible for us to rename versions.
Steps to reproduce:
- Create a filter that searches for a matching Fix Version which is assigned to at least one issue
- Using that filter returns the resulting matching issues as expected
- Rename the Fix Version on that project
- The filter will no longer return any results