Data import error

Each week, I import (clipboard) a specific type of data to the same table in my app. Today I attempted to import as I always do, and was presented with this error:

"The following required fields are missing from your import data: `Deliverable Cycle Month`"
(it does this for different req'd fields if I add the one it mentions to the clipboard import).

The app hasn't changed and the import data format hasn't changed. Has something in Quickbase changed that would cause this error?