Uniform Mutation trying to mutate genes outside of the chromossome array

[JJ223]

I am using Genetic Sharp to generate the Best team of Drones for a mission. Each gene in my chromossome stores the amount of a specific type of drone. The algorithm works perfectly fine except sometimes when performing a Uniform mutation it will try to change a gene outside of the chromossome. How could this happen? Am I doing something wrong?

Here is my code:

• Chromossome

  public class TeamChromosome : ChromosomeBase
  {
  private readonly int[] _maxAmounts;
  
  public TeamChromosome(int[] maxAmounts) : base(maxAmounts.Length)
  {
      _maxAmounts = maxAmounts;
      CreateGenes();
  }
  
  public override IChromosome CreateNew()
  {
      return new TeamChromosome(_maxAmounts);
  }
  
  public override Gene GenerateGene(int geneIndex)
  {
      // Generate random gene value within the maximum amount for the type
      return new Gene(RandomizationProvider.Current.GetInt(0, _maxAmounts[geneIndex] + 1));
  }
  }

  And my fitness Function

  public class DroneTeamFitness : IFitness
  {
  private MissionPlanner missionPlanner;
  private List<int> quantities;
  private List<List<Drone>> capableDrones;
  private bool basedOnTime;
  
  public DroneTeamFitness(MissionPlanner missionPlanner, List<int> quantities, List<List<Drone>> capableDrones, bool basedOnTime)
  {
      this.missionPlanner = missionPlanner;
      this.quantities = quantities;
      this.capableDrones = capableDrones;
      this.basedOnTime = basedOnTime;
  }
  
  public double Evaluate(IChromosome chromosome)
  {
      var genes = chromosome.GetGenes();
      List<Drone> team = new List<Drone>();
  
      int droneIndex = 0;
      for(int i = 0; i < quantities.Count; i++)
      {
          int count = 0;
          foreach(Drone drone in capableDrones[i])
          {
              count += (int)genes[droneIndex].Value;
              for(int j = 0; j < (int)genes[droneIndex].Value; j++)
              {
                  team.Add(drone);
              }
              droneIndex++;
          }
          if(count > quantities[i])
          {
              return 0;
          }
      }
      // Check if the team is empty
      if(team.Count == 0)
      {
          return 0;
      }
  
      (List <Drone> teamOverWater, List <Drone> teamUnderWater) = missionPlanner.assignDroneToWorkingArea(team);
  
      // Check if the team can perform the mission
      Mission mission = missionPlanner.mission;
      if ((mission.HeigthLimit.upperLimit > 0 && teamOverWater.Count == 0) || mission.HeigthLimit.lowerLimit < 0 && teamUnderWater.Count == 0)
          return 0;
  
      List<List<DronePath>> missionPaths = missionPlanner.PlanMission(teamOverWater, teamUnderWater);
      double missionCost = PathEvaluation.calculateMissionCost(missionPaths);
      double missionTime = PathEvaluation.calculateMissionTime(missionPaths);
      // You can add more criteria to evaluate the fitness
  
      if (basedOnTime)
      {
          return 1 / missionTime;
      }
      return 1 / missionCost;
  }
  }

[JJ223]

Managed to fix it by changing the UniformMutation constructer from UniforMutation(true) to UniformMutation(mutableGenesIndexes) with the indexes of the chromossome.