Serious Error in Lot Size calculation in MT4

So, if the Lot Step (e.g 0.2, 0.25, ...) is not a standard one, all trades fail with ErrorSend error 131.


This could be easily fixed adding the yellow code lines in the sqMMFixedAmount function (taken from the embedded fixLotSize function of the OrderReliable Library, which actually is not used)


double sqMMFixedAmount(string symbol, int orderType, double price, double sl, double RiskedMoney, int decimals, double LotsIfNoMM, double MaximumLots) {
   Verbose("Computing Money Management for order - Fixed amount");
   
   if(UseMoneyManagement == false) {
      Verbose("Use Money Management = false, MM not used");
      return (mmLotsIfNoMM);
   }
   
   symbol = correctSymbol(symbol);
   sl = NormalizeDouble(sl, (int) MarketInfo(symbol, MODE_DIGITS));
   
   double openPrice = price > 0 ? price : (orderType == OP_BUY ? sqGetAsk(symbol) : sqGetBid(symbol));
   double LotSize=0;


   if(RiskedMoney <= 0 ) {
      Verbose("Computing Money Management - Incorrect RiskedMoney value, it must be above 0");
      return(0);
   }
   
   double PointValue = MarketInfo(symbol, MODE_TICKVALUE) / MarketInfo(symbol, MODE_TICKSIZE);   
   double Smallest_Lot = MarketInfo(symbol, MODE_MINLOT);
   double Largest_Lot = MarketInfo(symbol, MODE_MAXLOT);    
   double LotStep = MarketInfo(symbol, MODE_LOTSTEP);

   //Maximum drawdown of this order if we buy 1 lot 
   double oneLotSLDrawdown = PointValue * MathAbs(openPrice - sl);

   if(oneLotSLDrawdown > 0) {
  LotSize = roundDown(RiskedMoney / oneLotSLDrawdown, decimals);
  
  double mod = MathMod(LotSize, LotStep);
          if(MathAbs(mod - LotStep) > 0.000001){
               LotSize -= mod;
     }
   }
   else {
  LotSize = 0;
   }
........