Here you go my friend.
Message: Object reference not set to an instance of an object.
InnerException:
Stack Trace: at Microsoft.Xna.Framework.Audio.SoundBank.PlayCue(String name)
at StardewValley.Game1.playSound(String cueName)
at StardewValley.TemporaryAnimatedSprite.update(GameTime time)
at StardewValley.GameLocation.updateEvenIfFarmerIsntHere(GameTime time, Boolean ignoreWasUpdatedFlush)
at StardewValley.Game1.UpdateLocations(GameTime time)
at StardewValley.Game1.Update(GameTime 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 StardewValley.Program.Main(String[] args)

Mmm this looks like something entirely caused by Stardew and not SMAPI. What version of SDV are you using?

I keep my SDV at the "Always keep this game up to date" option in the Steam Stardew Valley - Properties.

Also the latest update was on the 29th of april.

Hi there,
Just to check, does the game run as normal without SMAPI?

Yes and it runs fine with SMAPI.

Mmm I'd suggest posting a thread over in the forum here: http://community.playstarbound.com/forums/mods.215/

Haven't ran into this error before and I'm not too sure if SMAPI is causing it.

CJB Item Spawner Mod

My guess is that it's something to do with your audio. If the game plays fine without SMAPI I suggest playing without mods now and maybe asking on the forum to see if anyone else has run into it.