Cannot save new sliders

When saving settings the plugin sticks on Sending Data – the timer keeps going round for ever. When I view or preview a page with the slider I am working on, nothing loads after the h1.entry-title – the page after that is white. Additionally there is a white bar at the top of the page, where the WordPress admin toolbar should be. So I cannot press Edit, I have to login to domain.com/wp-admin to edit the page with the slider. I am no longer able to create new sliders because the settings won’t save.

I deactivated all plugins including Jetpack and it made no difference.

Master Slider has previously been working fine.

The page I need help with: [log in to see the link]