问请问什么情况下appinventor2会出现这种错误反馈？

请问为什么会出现这种情况？

The operation is list empty? cannot accept the arguments: [java.util.GregorianCalendar[time=1570894819204,areFieldsSet=true,lenient=true,zone=Asia/Shanghai,firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2019,MONTH=9,WEEK_OF_YEAR=41,WEEK_OF_MONTH=2,DAY_OF_MONTH=12,DAY_OF_YEAR=285,DAY_OF_WEEK=7,DAY_OF_WEEK_IN_MONTH=2,AM_PM=1,HOUR=11,HOUR_OF_DAY=23,MINUTE=40,SECOND=19,MILLISECOND=204,ZONE_OFFSET=28800000,DST_OFFSET=0]]

注意： 5秒钟后将报告另一条错误信息。