Believe this needs an expert familiar on the arrays of Structure !!!

Please refer to the screenshot below.  

Why does the "Experts Log" always say "array out of range" even though I changed "symbolCount" in line 37 into '0'?  

Below is the complete code.  

#property strict
input string ExClude="#";
input string Prefix="";
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
struct Valid
  {
   string            name;
   int               POS;
  };
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+         
void symbolFilter()
  {

   Valid validSymbol[];
   int i,preLen=StringLen(Prefix)-1,symbolCount=0,arraySize;
   int   totalPOS=SymbolsTotal(true);  //Dont't forget to "Show All" in "Market Watch"
   string Display=" ",symbolName;
//---  
   for(i=0;i<totalPOS;i++)
     {//use 'true' in order to be consistent with the sequence in "Market Watch"   
      //filter symbols with "ExClude" 
      symbolName=SymbolName(i,true);
      if(StringFind(symbolName,ExClude,preLen)==-1)
        {
         validSymbol[symbolCount].name=symbolName;
         validSymbol[symbolCount].POS=i;
         arraySize=ArraySize(validSymbol);
         if(++symbolCount>=arraySize) ArrayResize(validSymbol,arraySize+1);
        }
     }
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int OnInit()
  {
//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   Comment("");
   Print(__FUNCTION__,"_Uninitalization reason code = ",reason);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void OnTick()
  {
   symbolFilter();
  }
//+------------------------------------------------------------------+