I wanted 3 MA lines in different colors, so I wrote an indicator with three MAs. If I drop it on a chart it works perfectly, but I just can't seem to call it from the EA. The error message in the log is:

2025.06.15 01:03:22.316 2025.06.09 02:14:39 cannot open file 'F:\FOREX_DEMO\MQL4\indicators\MAs_Ind.ex4' [2]

I can't find an explaination for the [2]

Here's the call:

double MA_Lines = iCustom(NULL,0,"MAs_Ind",FastMA_Periods,2,0,MidlMA_Periods,2,0,SlowMA_Periods,2,0,1,0,0);

Here's the code:

#property description "MAs_Ind"
#property indicator_chart_window
#property strict
#property indicator_buffers 3
#property indicator_color1 Yellow
#property indicator_color2 Red
#property indicator_color3 Blue

double Buffer1[];
double Buffer2[];
double Buffer3[];

extern int MA1_Periods = 5;    // number of periods used in calc of the MA line, 0=don't show this line
extern int MA1_Method  = 2;    // 0=Simple Moving Average, 1=Exponential Moving Average, 2=Smoothed Moving Average, 3=Linear Weighted Moving Average
extern int MA1_Price   = 0;    // 0=close, 1=open, 2=high, 3=low, 4=median(h+l/2), 5=typical(h+l+c/3),6=weighted close(h+l+c+c/4) used for slope calc
extern int MA2_Periods = 15;   // the number of periods to use in calculating a moving average line as a Stop Loss, 0=don't show this line
extern int MA2_Method  = 2;    // 0=Simple Moving Average, 1=Exponential Moving Average, 2=Smoothed Moving Average, 3=Linear Weighted Moving Average
extern int MA2_Price   = 0;    // 0=close, 1=open, 2=high, 3=low, 4=median(h+l/2), 5=typical(h+l+c/3),6=weighted close(h+l+c+c/4) used for slope calc
extern int MA3_Periods = 50;   // the number of periods to use in calculating a moving average line to determine whether to take positions, 0=don't show this line
extern int MA3_Method  = 0;    // 0=Simple Moving Average, 1=Exponential Moving Average, 2=Smoothed Moving Average, 3=Linear Weighted Moving Average
extern int MA3_Price   = 0;    // 0=close, 1=open, 2=high, 3=low, 4=median(h+l/2), 5=typical(h+l+c/3),6=weighted close(h+l+c+c/4) used for slope calc
extern int Line_Width  = 1;    // width of indicator lines

int OnInit()
{
   IndicatorShortName("MAs");

   SetIndexStyle(0,DRAW_LINE,EMPTY,Line_Width);
   SetIndexBuffer(0,Buffer1);
   SetIndexLabel(0,"MA"+IntegerToString(MA1_Periods));
   SetIndexEmptyValue(0,0.0);

   SetIndexStyle(1,DRAW_LINE,EMPTY,Line_Width);
   SetIndexBuffer(1,Buffer2);
   SetIndexLabel(1,"MA"+IntegerToString(MA2_Periods));
   SetIndexEmptyValue(1,0.0);

   SetIndexStyle(2,DRAW_LINE,EMPTY,Line_Width);
   SetIndexBuffer(2,Buffer3);
   SetIndexLabel(2,"MA"+IntegerToString(MA3_Periods));
   SetIndexEmptyValue(1,0.0);

   for(int i=1; i<=ObjectsTotal(); i++) if ( StringSubstr(ObjectName(i),0,7) == "MAs_Ind" ) ObjectDelete(ObjectName);

   return(0);
}


int deinit()
{
   return(0);
}


int OnCalculate(const int rates_total,      // size of input time series 
                const int prev_calculated,  // bars handled in previous call 
                const datetime& time[],     // Time 
                const double& open[],       // Open 
                const double& high[],       // High 
                const double& low[],        // Low 
                const double& close[],      // Close 
                const long& tick_volume[],  // Tick Volume 
                const long& volume[],       // Real Volume 
                const int& spread[]         // Spread 
                )
{
   int limit=rates_total-prev_calculated;
   for(int i=0; i<limit; i++)
      {
      Buffer1[i]=iMA(NULL,0,MA1_Periods,0,MA1_Method,MA1_Price,i);
      if (MA2_Periods > 0 ) Buffer2[i]=iMA(NULL,0,MA2_Periods,0,MA2_Method,MA2_Price,i);
      if (MA3_Periods > 0 ) Buffer3[i]=iMA(NULL,0,MA3_Periods,0,MA3_Method,MA3_Price,i);
      }
      
   return(0);
}

#include <WinUser32.mqh>

//  end of text

Any help is greatly appreciated; when I drag it from the indicators list on the left, I have to put in the 10 parameters that the it should pickup from the call. Of course, if you use any of the indicator code it's at your own risk; I take no responsibility for the code's accuracy or functionality.

Long story short : proper case matters

Your error-message reads :

"(...)
2025.06.15 01:03:22.316 2025.06.09 02:14:39 cannot open file 'F:\FOREX_DEMO\MQL4\indicators\MAs_Ind.ex4' [2]"

However, the standard MQL4 installation demands this :

"Custom indicators are stored in <_terminal_directory_>\MQL4\Indicators"

Solution :

Use proper case ( typing Indicators instead of indicators ) and the compilation ought find the file, where it ought be, and continues its work.