Because you have calculation period somewhere in your code and it returns a null or negative value. You might be able to fix this with ABS instruction.

If it doesn’t work, please post your code for a complete explanation of what happened.

Hi all,

since I ran into the issue which Gordon Gekko describes, I would like to show you how I solved it for my case.
The original code was:

...
IF NOT ONMARKET and (some conditions true) THEN
BUY 3 CONTRACT AT MARKET
ENDIF
...
IF LONGONMARKET AND (highest[BarIndex - TradeIndex](high) < something) THEN
do something ;-)
ENDIF
...

In every every trade, when the first candle ran through and the system tried to evaluate the next candle, it ran on error
“… system was stopped because the program used a negative or zero offset (ex: close[-10]) during the evaluation of the last candlestick. …”

I solved it by just preventing the code to check “BarIndex – TradeIndex” when it is 0. This is always 0 in the first candle of the trade. So I added a simple condition to my code so that it looks as follows:

...
IF NOT ONMARKET and (some conditions true) THEN
BUY 3 CONTRACT AT MARKET
ENDIF
...
IF BarIndex - TradeIndex > 0 THEN
IF LONGONMARKET AND (highest[BarIndex - TradeIndex](high) < something) THEN
do something ;-)
ENDIF
ENDIF
...

This worked well and the system doesn’t stop anymore 🙂