Description
You selected SPACE TIME WINDOW but did not define a Date/Time Interval Value. The SPACE TIME WINDOW Conceptualization of Spatial Relationships requires you to define a Date/Time Field, Interval Type, and Interval Value.
Solution
Specify a numeric value for the Date/Time Interval Value field. If you think two features with time stamps (your Date/Time field) within two days of each other will be related, for example, you would set the Interval Value to 2.