Cannot-change-access-modifiers-when-overriding-public-inherited-member

Execute() is public, not protected like it was in WL6.

Also, instead of this -

CODE:
      // Ensure there is enough data to calculate both SMAs
      if (idx < Math.Max(Parameters[0].AsInt, Parameters[1].AsInt))
         return;

Put this at the end of Initialize(). This also sets the start of the Benchmark backtest.

CODE:
StartIndex = Math.Max(Parameters[0].AsInt, Parameters[1].AsInt);

And for the Cadillac version,
1. modify conditions to use CrossesOver/Under.
2. create Parameter variables instead of the Parameters[] index. It's okay for a script with a couple variables, but when you have more than 3 or 4, it gets confusing quickly.
3. Finally, if you're at all interest in doing WFO, get in the habit of adding the NewWFOInterval method and calling it from Initialize().

CODE:
using WealthLab.Backtest;
using System;
using WealthLab.Core;   
using WealthLab.Data;
using WealthLab.Indicators;
using System.Collections.Generic;
using System.Drawing;

public class SMACrossover : UserStrategyBase
{

   public SMACrossover()
   {
      // Add parameters to allow flexibility in the strategy
      _fast = AddParameter("Fast SMA Period", ParameterType.Int32, 10, 1, 100, 1);
      _slow = AddParameter("Slow SMA Period", ParameterType.Int32, 20, 1, 200, 1);
   }

   public override void Initialize(BarHistory bars)
   {
      NewWFOInterval(bars);
      
      // Plot the Fast SMA and Slow SMA on the chart
      PlotIndicator(slowSMA, WLColor.Blue);
      PlotIndicator(fastSMA, WLColor.Green);      
      StartIndex = Math.Max(_fast.AsInt, _slow.AsInt);
   }

   public override void NewWFOInterval(BarHistory bars)
   {
      //recreate the indicators for each WFO interval here
      fastSMA = new SMA(bars.Close, _fast.AsInt);
      slowSMA = new SMA(bars.Close, _slow.AsInt);
   }

   public override void Execute(BarHistory bars, int idx)
   {
      // Check for a crossover condition
      // Buy signal: Fast SMA crosses above Slow SMA
      if (fastSMA.CrossesOver(slowSMA, idx))
      {
         PlaceTrade(bars, TransactionType.Buy, OrderType.Market);
      }

      // Sell signal: Fast SMA crosses below Slow SMA
      else if (fastSMA.CrossesUnder(slowSMA, idx))
      {
         PlaceTrade(bars, TransactionType.Sell, OrderType.Market);
      }
   }


    // Declare variables for fast and slow SMA 
    private SMA fastSMA;
   private SMA slowSMA;

   Parameter _fast;
   Parameter _slow;   
}

You also should modify the Parameter ranges to make better sense and maybe increment in steps of 2 or 5.

QUOTE:
Execute() is public, not protected like it was in WL6.

Thanks for this info, but what did I do to attempt to override the inherited member? That is what I am having trouble understanding. Where did that occur?

Subtle error on my part but absolutely important. Thanks Glitch!

QUOTE:
Put this at the end of Initialize(). This also sets the start of the Benchmark backtest.
CODE:
StartIndex = Math.Max(Parameters[0].AsInt, Parameters[1].AsInt);

Cone, thanks for this bit of info. Need to start learning these details.

V