Editing existing calculated fields does not work either. Cannot add fields by double clicking
Thank you for your posts.
When you say, "14.0.6 Mac Filemaker Advanced on the latest current operating system", is this Mac OS X 10.11.6 or Windows 10?
Regardless, on your computer, create a new user account, login to the new user account, launch FileMaker Pro 14.0.6, create a new database file, and see if you are able to create a new Calculation field and double-click a field from the fields pane. Does this work? If so, then there is something in your original user account that is causing the issue. However, if this still doesn't work, then uninstall and reinstall FileMaker Pro, as this will write all new set of files.