FM 14: Actual bug with calculation fields (not a usability issue)

Issue report by scotty321

Product

FileMaker Pro

Version

14.0.1

Operating system version

OS X 10.10.4

Description of the issue

This is an actual bug with calculation fields in FileMaker Pro 14 (not a usability issue, but an actual bug):

1. Go into Manage Databases -> Fields.
2. Create a calculation field. The calculation field should be evaluated from the context of "Table Occurrence A" (choose your own table occurrence here).
3. Save all your changes (i.e. completely exit the "Manage Database" window.)
4. Go back into Manage Databases.
5. Go onto the Relationship Graph and delete "Table Occurrence A".
6. Go back into the calculation you defined above. It now shows that your calculation field is being evaluated from the context of <Unknown>. This is expected, but here is where the bug crops up:
7. YOU CAN NO LONGER CHANGE THE CONTEXT TO CHOOSE A DIFFERENT TABLE OCCURRENCE. You are forced to completely delete and rebuild the calculation from scratch. In all previous versions of FileMaker, you could simple choose a different table occurrence.

See screenshot below of the pop-up menu which can no longer be changed in FileMaker 14.

Screenshot