A new page was inserted but it does not contain any intersecting guides

This is displayed because EasyCatalog has inserted a new page however there is no intersecting guides to define where it will place the first item.

This is typically caused by guides being created on Page 1 rather than on the Master Spread however it can also be caused because only one page on the master spread has guides.
EasyCatalog Pagination Module - page does not contain any intersecting guides