Master Slider not working in new Keynote theme

I’ve just upgraded the Keynote theme and now the Master Slider wont work. When I go to edit an existing slider it just says ‘loading data…’ and goes no further. If I try to create a new slider it does exactly the same.

I can preview an existing master slider though and it displays fine and even thanks me,

Thank you for creating with WordPress. and using Master Slider 2.9.6

I’ve tried the master slider on the same site with a different theme and it works fine.

Any hints on what to do?