Application crashes if you right click anywhere in the filter window after a custom filter has been added

[Anacondo]

Another weird bug I found, this one is quite self-explanatory:

This doesn't happen if no saved filters exist. Happens both for video and audio filters. Here's the crash log:

System.NullReferenceException: Object reference not set to an instance of an object. at Av1ador.Form1.<VfListBox_MouseUp>b__116_0(String s) at System.Collections.Generic.List1.FindIndex(Int32 startIndex, Int32 count, Predicate1 match) at System.Collections.Generic.List1.FindIndex(Predicate1 match) at Av1ador.Form1.VfListBox_MouseUp(Object sender, MouseEventArgs e) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ListBox.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at Av1ador.Program.Main()