Sorry my bad - I had been testing using the Pie chart, not Pyramid. I had changed it from Pie to Pyramid while troubleshooting and forgot to change it back before posting.
I've just tested again using cfx.Gallery.Bar and still getting the same error:
chart1.setGallery(cfx.Gallery.Bar); "Unhandled exception at line 599, column 429 in http://localhost:59748/jChartFX/js/jchartfx.coreVector.js 0x800a138f - JavaScript runtime error: Unable to get property 'call' of undefined or null reference"