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
JEvents Club members can get priority forum support at the Support Forum. As well as access to a variety of custom JEvents addons and benefits.
Join the JEvents club today!