Content in the page is disabled after i click Select

Hi, I have been using this great extension for quite sometime now, but yesterday when i wanted to use it after almost 6 motnhs it wont let me create a sitemap.

After creating the new sitemap when i start adding selectors. I can not because the content in the page is sort of disabled after I click on the select button.

Please help me.

Url: http://farfetch.com

Sitemap:
{"_id":"ffetch","startUrl":["https://www.farfetch.com/ve/designers/men"],"selectors":[]}