Please help: Getting "Array Out of Range" in EA

Hello,
I'm studying MQL and I created an EA, but when I run it, Journal gives me "Array Out of Range" each time it tries to buy or sell.

This is the code:

if(SignalToday > Close[i] && SignalYesterday < Close[i+1]){ // <- This line is the one that Journal says has the error
signalBufferBuy[i] = 1;
signalBufferSell[i] = 0;
}

SignalToday is taken from an iCustom("Signal",0, i)
SignalYesterday is taken from an iCustom("Signal",0 ,i+1)
Signal.ex4 is a bought indicator so I can't give the code. All I know is that if I test the indicator alone in MT4 dragging it to the Price window, the signals are displayed correctly. Basically it's a Moving Average that I'd like to know if it's above or under the close, so if it's below yesterday's close but above today's close, then enter.
The strange thing is that if I change the indicator in the iCustom, with some work and with some doesn't.

Any help would be greatly appreciated.

Close[i+1] is the culprit ... +1 is going past the available Bars.

Thanks for the reply, FerruFX.
But Close[i+1] is not last bar's Close?
If it's daily chart, Close[i] would be today's close and Close[i+1] would be yesterday's close, right?

If I use the indicator in a chart window, values are displayed correctly: when Moving Average crosses the close, it draws the line on the histogram in the indicator's window.

Try adding in if(i<(Bars-1)) before that line of code, its a quick fix that has worked for me in the past.

Your post is confusing.
You sat that you are creating an EA, yet the use of array name "signalBufferBuy" suggests that you are using buffers. EAs do not have buffers.
Usually an EA has no need to loop through all historical bars as it only needs to retrieve the current signals.
Of course, I don't know what the logic is behind the EA, but
if(SignalToday > Close[1] && SignalYesterday < Close[2])
or something similar would normally be all that is required (if working with closed bars)

Yes and that's exactly the problem when i==Bars ... so i+1 is over the Bars available ...

CJA fix is all you need to get ride of the error.

Thanks for the help, guys. I really appreciate it.
It's a buffer because this code is from the indicator that will be called from the EA with iCustom()

I think I understood and did it correctly. But now, when I try to test it on visual mode, I get no signals. Oddly, if I insert the indicator to the Chart where the price move (Visual Mode), the bars from the indicator do show the signals for the days before the test began, but not the signals while it's testing.
But when the test stops, the window that shows up automatically, does have all the bars with the signals.
Journal doesn't show any errors.

This is the code I used:

if(i<(Bars-1))
{
if(SignalToday > Close[i] && SignalYesterday < Close[i+1]){
signalBufferBuy[i] = 1;
signalBufferSell[i] = 0;
} else
if(SignalToday < Close[i] && SignalYesterday > Close[i+1]){
signalBufferBuy[i] = 0;
signalBufferSell[i] = 1;

} else {
signalBufferBuy[i] = 0;
signalBufferSell[i] = 0;
}
}

How did you declare the Array?
What size is it?
An indicator will manage the array differently to an EA, so you need to ensure you have a sufficiently large array to hold all the expected values.