Create Sidebars Not working in Widgets Area

I am having a problem using the plugin on ifeature Pro 5.

Ever since updating custom sidebars I cannot add a sidebar using the widgets section. If I hit the create new sidebar button and name and then create, it just hangs with the wheel turning constantly.

I have one site on the ifeature 5 Free version which I have just installed custom sidebars on, and the same thing happens… go to widgets, try to create and it just hangs?

Was all working fine before the last update, but now I can’t create a sidebar?

One of the sites I use them on for reference: http://www.enviromontel.co.uk

Any ideas?

Thanks
Paul

https://ww.wp.xz.cn/plugins/custom-sidebars/