This should be created automatically when you edit your layouts. I checked your site and it appears you have a layout for categoryid=42 and language =en-GB setup which was stopping the blank version from being created. It looks as through the original entry had been deleted in the database somehow - don't know how as we don't do this within JEvents.

I have resolved this on your site and a code change will stop it from happening again when the next release of JEvents comes out