JAVA

how to solve CopyBuffer from HiLo failed, no data

//---------------- Middle MA
if(CopyBuffer(ExtMiddleHandle, 0, startFromIndex, bufferSize, ExtMiddleBuffer) < 2)  
  {  
   Print("Loading ExtMiddleHandle failed ", GetLastError());
  }  
ENUM_ORDER_TYPE middleDir = ExtMiddleBuffer[0] == ExtMiddleBuffer[1] ? NULL : (ExtMiddleBuffer[0] < ExtMiddleBuffer[1] ? ORDER_TYPE_BUY : ORDER_TYPE_SELL);

//---------------- Slow MA  
if(CopyBuffer(ExtSlowHandle, 0, startFromIndex, bufferSize, ExtSlowBuffer) < 2)  
  {  
   Print("Loading ExtSlowHandle failed ", GetLastError());
  }  
ENUM_ORDER_TYPE slowDir = ExtSlowBuffer[0] == ExtSlowBuffer[1] ? NULL : (ExtSlowBuffer[0] < ExtSlowBuffer[1] ? ORDER_TYPE_BUY : ORDER_TYPE_SELL);