Issues with Storyline 2 and HTML5 variables

I'm somewhat new to Storyline and have been working on a large project to create an interactive game. At about halfway through the development phase I noticed that the HTML5 output is broken, whereas the Flash published previews have been working flawlessly. After a lot of testing I have narrowed the problem down to variables under HTML5. I have used a numerical variable called "slideprogress" which triggers textboxes to appear when the user clicks. Each element appears when the associated number of clicks occurs and the slideprogress variable changes, so textbox 1 appears after 1 click and so on. As soon as the variable "slideprogress" is changed by a user clicking the background image.. the timeline hangs with the circular loading animation. A small excerpt of the storyline file has been attached to this message below.  A couple of slides in the problem occurs, and if you click the red skip button it will make it a bit further in the story before also freezing with the same problem.

I'm at a loss on how to best solve this problem. I do need HTML5 support so I am wondering whether this is a bug that can be fixed or if there is another way to progress a slide using clicks  without using variables in this way. Any help is most appreciated!!