Error in formula from Tradescript.pdf manual

Hi, I am a well experience software programmer, getting to field of trading. I am trying to setup scanner, some of them are working. i have problem in the following script for bearishEngulf CANDLESTICKPATTERN() = BEARISH_ENGULFING_LINE AND TREND(CLOSE, 30) = UP AND VOLUME > REF(VOLUME, 1) when i click Load, getting “Your script generated an error”. I tried debugging little bit, if i remove the third condition it runs properly. Please advice whats error.