Trimming a Lengthy Segment in Captivate 7

I am using Captivate 7 in a Windows 10 environment.

An Adobe video says that when I select Window --> Timeline, I should see the entire timeline for my video. I do not, I see only a section of it.

The segment I want to trim extends beyond the physical length of the timeline in the Captivate window. In other words, the visible timeline goes from 0 to 1:08, but the section I want to trim goes from 0 to 4:12. I cannot figure out how to select the entire section. The trim endpoints even seem to jump around if I grab one of them and attempt to scroll to the starting point, or ending point, of the area I want to trim.

I would prefer not to have to trim one short segment after another until I achieve the complete length. There must be a way to select a lengthy portion of a video and trim it. All suggestions gratefully received.

--Nancy