Kimber,
I am having the exact same problem.
I made a test Lesson with a cluster to figure it out. What I've learned is that it seems to behave properly when you're previewing it as a teacher (because it replaces the "Jump to Unseen Question in Cluster" jump with "Next Page" jumps).
However, when you switch your role to student, and have seen all of the questions*, it dumps me to an error without showing me the last content page of the Lesson ("Could not find lesson pages").
If I click on Continue at this point, it dumps me to the Site Home, and the course I was just working in no longer shows up in the "All Courses" list. That bit is especially weird.
The structure of my Lesson is:
1st content page (CP1): Jumps to "Next Page" which is the beginning of the Cluster
Cluster: Jumps to "Unseen quustion within a cluster"
Question Page 1 (QP1): Right answer jump: "Unseen question within a cluster", wrong answer jump: "1st content page"
Question Page 2: (QP2): Right answer jump: "Unseen question within a cluster", wrong answer jump: "1st content page"
End of cluster: Jumps to "Next page"
Last content page (Jump to "End of Lesson")
* As an example, if I deliberately answer the first QP (let's say QP1) it gives me wrong, go back to CP1 and click continue, then answer QP2 wrong, back to CP1 and click continue, it errors out ("Could not find lesson pages.") I can get that to happen every time.
The same thing happens if I click the correct response on one of the questions, which takes me to the next question, then click the wrong answer, get taken back to CP1, then click "Continue."
And, oddly enough, if I get both questions correct, it completely skips the last Content Page and takes me directly to the End of Lesson page.
As a side note, I'm not clear on how the Cluster "Unseen Question" jump is supposed to work. Does it mean actually "seeing it" and not "seeing it and getting the question right"? How do I make sure that the student has to get the questions right before moving on in a Cluster situation?