Bug: Inconsistent use of Display & Interlinear buttons

This occurs in resources when Interlinear text is not available for certain books. For example, one resource shows a blank Interlinear panel whilst another shows no panel. The Display button continues to be shown when there is no inline text.

Software version: 4.0c SR-1.
Reported by Dave Hooton.
Forum link: https://logos.vanillacommunities.com/forums/t/18006.aspx
Status: confirmed