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 Date/Time Field, Date/Time Interval Type, and Date/Time Interval Value values.
Solution
Specify a numeric value for the Date/Time Interval Value field. For example, if you think that two features with time stamps (your Date/Time Field value) within two days of each other will be related, set Date/Time Interval Value to 2.