Logos 7.15 Beta 4 Mac OS 10.13.4
This may have occurred prior to Beta 4, but I don't remember encountering it prior to Beta 4.
Every time I open the Courses Tool and select a video, the video window appears, but the transcript is missing. It does no matter which course or which video within the course.

In order to restore correct operation, I must start another course—or delete the current one and restart. Then the transcript will appear.

The second screenshot was taken about 30 seconds after the first one, after I deleted OT312 and restarted it.