在数据列>高级>结果集筛选，按照分栏教学内容在制定状态下输入=joinarray(greparray(range($_count_),item % 3 == 1),",")运行报错。

ava.lang.NullPointerException
	at com.fr.function.RANGE.rangeNumber(Unknown Source)
	at com.fr.function.RANGE.run(Unknown Source)
	at com.fr.script.AbstractFunction.tryRun(Unknown Source)
	at com.fr.script.AbstractFunction.evalExpression(Unknown Source)
	at com.fr.parser.FunctionCall.eval(Unknown Source)
	at com.fr.script.Calculator.eval(Unknown Source)
	at com.fr.script.Calculator.evalValue(Unknown Source)
	at com.fr.function.LambdaFunction.evalExpression(Unknown Source)
	at com.fr.parser.FunctionCall.eval(Unknown Source)
	at com.fr.script.Calculator.eval(Unknown Source)
	at com.fr.script.Calculator.evalValue(Unknown Source)
	at com.fr.script.AbstractFunction.evalExpression(Unknown Source)
	at com.fr.parser.FunctionCall.eval(Unknown Source)
	at com.fr.script.Calculator.eval(Unknown Source)
	at com.fr.stable.script.Expression.eval(Unknown Source)
	at com.fr.script.Calculator.evalString(Unknown Source)

请问怎么回事