I'm having an issue when I add new users in bulk using this

Hi,
I'm having an issue when I add new users in bulk using this plugin. I don't get any errors it just gets stuck in what looks like a loop.

Once I've filled in the details for the new users and click next I get taken to the screen which says "adding users..." and then nothing happens. The page continues to load and I can see from the tab that it is still doing something but I've left this for 15 minutes and it never finishes the process. If I close the page and log back in the users have not been added. It is difficult to describe but if you go into the myechef.co.uk site and add new users you can see what its doing. I have granted you support access.

I do have the latest version of the plugin and WordPress is up to date, is this a known issue?