Lync SDK 2013 presence indicator causes null reference exception on close

Hello, I'm new here and new to the Skype For Business/Lync SDK. So I hope I'm posting this question in the right space.

So I added a presence indicator control to my Winforms app, and the weird thing is that after hovering over it to bring up a contact card, it'll cause a null reference exception when I close my application. (Opening and closing the app without hovering over the presence indicator won't throw the exception, but the control is still there and correctly color-coded with the user's presence.) This also only happens when bringing up the contact card for users other than myself.

Since this is my first time working with the Lync SDK, so I'm wondering if there's something I should be doing to dispose of the Lync controls before closing? What about the contact card might be causing a null reference exception?

Here's the stack trace for the null reference exception:

at Microsoft.Lync.Controls.Internal.Model.OcomModel.GroupsModel.UnwireGroupdAddRemove()  
at Microsoft.Lync.Controls.Internal.Model.OcomModel.GroupsModel.Dispose(Boolean disposing) 
at Microsoft.Lync.Controls.Internal.Framework.Common.UCBaseModel'1.Dispose()
at Microsoft.Lync.Controls.Internal.Model.OcomModel.ContactsAndGroupsManagerModel.Dispose(Boolean disposing) 
at Microsoft.Lync.Controls.Internal.Framework.Common.UCBaseModel'1.Dispose()  
at Microsoft.Lync.Controls.Internal.Model.OcomModel.UCClientModel.DisposeModels()   
at Microsoft.Lync.Controls.Internal.Model.OcomModel.UCClientModel.Dispose(Boolean disposing   
at Microsoft.Lync.Controls.Internal.Framework.Common.UCBaseModel`1.Dispose()  
at Microsoft.Lync.Controls.LyncServiceProvider.DisposeUcClientModel() 
at Microsoft.Lync.Controls.LyncServiceProvider.HandleWindowsFormsApplicationExit(Object sender, EventArgs e)  
at System.Windows.Forms.Application.RaiseExit() 
at System.Windows.Forms.Application.ThreadContext.Dispose(Boolean postQuit)  
at System.Windows.Forms.Application.ThreadContext.ExitCommon(Boolean disposing)  
at System.Windows.Forms.Application.ExitInternal()  
at System.Windows.Forms.Application.Exit(CancelEventArgs e)  
at System.Windows.Forms.Application.Exit()
at Console.Program.Main(String[] args)