Crashing when entering 4th answer in question?

Hi all,

I've opened a project I prepared a few months ago - no issue with adding questions or anything when I originally published the module.

I'm trying to add some further graded questions, however when I try to add a 4th option to the answers, Storyline keeps crashing.

Peek video:

https://360.articulate.com/review/content/753fe5d5-aea2-40f9-8b75-f77b7aa02d09/review

(P.S. there's a lot of deadtime at end of the Peek.....the GUI had disappeared so I had to google the shortcut to end the recording)

. I haven't gone through each question type one by one, but it has happened with multiple types of questions.

Any ideas what it causing this? This has been happening for a few weeks. I downloaded the most recent Storyline 360 updates yesterday so it should be up to date.

Thanks in advance,

Michelle