.Net Framework Error every time animals around.... Help

  • So, I am trying to play a bit of "Single player" Eco. By running the server on the same machine I am playing the game on.

    Everything seems to work fine until I get into areas will a decent amount of animal (Usually over 7) I get this .Net Framework error. The game does not crash just seems to remove most of the animals around.

    Any ideas of suggestions would be great.

    .Net Framework Error:

    See the end of this message for details on invoking
    just-in-time (JIT) debugging instead of this dialog box.

    ************** Exception Text **************
    C5.CollectionModifiedException: Exception of type 'C5.CollectionModifiedException' was thrown.
    at C5.IntervalHeap1.<GetEnumerator>d__46.MoveNext() at System.Linq.Enumerable.<OfTypeIterator>d__921.MoveNext()
    at System.Linq.Lookup2.Create[TSource](IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer1 comparer) at System.Linq.GroupedEnumerable3.GetEnumerator()
    at System.Linq.Enumerable.WhereSelectEnumerableIterator2.MoveNext() at System.Linq.Buffer1..ctor(IEnumerable1 source) at System.Linq.OrderedEnumerable1.<GetEnumerator>d__1.MoveNext()
    at System.String.Join(String separator, IEnumerable1 values) at Eco.Simulation.OrganismSim2.ToString()
    at Eco.Simulation.AnimalSim.ToString()
    at Eco.Simulation.EcoSim.GetDisplayText()
    at Eco.Server.UI.ServerMainForm.<>c__DisplayClass5_0.<BuildDisplay>b__0(Object obj2, EventArgs args2)
    at System.Windows.Forms.Timer.OnTick(EventArgs e)
    at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m)
    at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)