iOS Forms App Crashing - Too Many Open Files?

Hi,

I am getting HockeyApp reports that the iOS version of a (fairly complex) app I have developed is crashing with an IOException 'Too many open files'.

The stacktrace doesn't tell me much of use but there's nothing in there that references my code and it seems to be caused by forms saving properties or something?

I seem to remember somewhere there was something built in to Forms for saving user setting etc - I don't use this, I use my own methods (using IsolatedStorage) but not of that is referenced here and I am sure to close and remove references to all streams,

Does anyone have any pointers as to what might be causing this and/or how to debug the issue. Unfortunately I can't afford access to the Xamarin profiling tools and XCode Instruments just locks up when I try to attach it to my app (which seems to be a common issue).

Thanks in advance.

=====

System.IO.IOException: Too many open files

System.IO.FileStream.FileStream(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool anonymous, FileOptions options)
System.IO.FileStream.FileStream(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, bool isAsync, bool anonymous)
System.IO.IsolatedStorage.IsolatedStorageFileStream.IsolatedStorageFileStream(string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, IsolatedStorageFile isf)
System.IO.IsolatedStorage.IsolatedStorageFileStream.IsolatedStorageFileStream(string path, FileMode mode, IsolatedStorageFile isf)
System.IO.IsolatedStorage.IsolatedStorageFile.OpenFile(string path, FileMode mode)
Xamarin.Forms.Platform.iOS.Deserializer.<>c__DisplayClass2_0.b__0()
System.Threading.Tasks.Task.InnerInvoke()
System.Threading.Tasks.Task.Execute()
Xamarin.Forms.Application.d__74.MoveNext()
Xamarin.Forms.Application.d__51.MoveNext()
Xamarin.Forms.Platform.iOS.FormsApplicationDelegate.d__8.MoveNext()
UIKit.UIKitSynchronizationContext.c__AnonStorey0.<>m__0()
Foundation.NSAsyncActionDispatcher.Apply()
UIKit.UIApplication.UIApplicationMain(int, string[], intptr, intptr)(wrapper managed-to-native)
UIKit.UIApplication.Main(string[] args, IntPtr principal, IntPtr delegate)
UIKit.UIApplication.Main(string[] args, string principalClassName, string delegateClassName)
OpenHouse.iOS.Application.Main(string[] args)