Next / Previous button in player not working on one slide in Storyline 360

Hello, 

I've opted to remove buttons in my project and use the buttons on the player... Unfortunately this project has a slide (one so far) where the buttons don't work.  The user then gets stuck in the learning module and can't go back or forward.  

I've also experienced a lot of crashing in the application after the update... anyone else?  and to add to matters... i'm to submit a link to a client for review by COB today, which means the client would get stuck 1/2 way through the course unable to go back or forward.