Buttons on quiz slides no longer functioning

Rod warned you already about the patch you forgot to install.

I am puzzled by your sentence that custom navigation used to work on quiz slides in previous versions. Quiz slides have a lot of embedded objects (have no timeline) which have functionality buitl in. Typical example is the Submit button, controlling the submit process. Why would you ever need custom navigation on a quiz slide? It is even dangerous because you have to use the Submit button for the two-step Submit process, and the learner will be navigated to the next slide after succes or last attempt for that quiz slide. Unless you are using the "Submit All functionality", offering navigation buttons to the learner will most likely end up in lot of quiz slides not answered at all. When a quiz slide is left (with the exception of the Remediation feature) the answers are blocked automatically even if attempts were not exhausted. That is very frustrating.

Maybe you can explain more in detail what you mean by that custom navigation (with shape buttons)?

If you are on Captivate 2017 10.0.0 then you are NOT on the latest update of that version.  You should update.

I am on the latest and I can confirm that there does not appear to be any issue with adding Smart Shape buttons to Quiz slides.  (You were definitely NOT trying to add other types of text buttons or image buttons to quiz slides, right?)

If after updating to 10.0.1 you still cannot insert a Smart Shape button on a quiz slide in your project, I would suggest doing a test with a completely different CPTX to see if the issue might be that your current CPTX is somehow corrupted.

Is this a responsive project or a normal project?