Error 704. In Rotational trading you MUST NOT use buy/sell/short/cover signals.

When trying to use the Rotational backtest mode you must not use buy/sell/short/cover variable assignments

EnableRotationalTrading();
SetOption("WorstRankHeld",5);

PositionSize = -25; // invest 25% of equity in single security
PositionScore = 50 - RSI(); // required for rotational mode

Buy = Cross( C, MA( C, 50 ) ); // WRONG - can not use that in rotational mode

On the other hand, if you want to use Buy/Sell/Short/Signals and just prioritize them - use regular backtest mode. For that, remove EnableRotationalTrading function call.

For more details see Rotational Trading mode