[FE7x crashes during combat animations]

Whenever a combat animation plays, the game crashes just as the unit is about to get hit. However, the game still works properly if I skip the combat animation. After the game crashes, a notepads titled "exception" comes up and in it, it says this:

8/11/2016 7:23:11 PM
System.Exception: Exception of type 'System.Exception' was thrown.
at FEXNA.Services.Rumble.RumbleService.Update(GameTime gameTime)
at  .Update(GameTime )
at Microsoft.Xna.Framework.Game.Tick()
at Microsoft.Xna.Framework.Game.HostIdle(Object sender, EventArgs e)
at Microsoft.Xna.Framework.GameHost.OnIdle()
at Microsoft.Xna.Framework.WindowsGameHost.RunOneFrame()
at Microsoft.Xna.Framework.WindowsGameHost.ApplicationIdle(Object sender, EventArgs e)
at System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FDoIdle(Int32 grfidlef)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr 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 System.Windows.Forms.Application.Run(Form mainForm)
at Microsoft.Xna.Framework.WindowsGameHost.Run()
at Microsoft.Xna.Framework.Game.RunGame(Boolean useBlockingRun)
at  .(String[] )