Xamarin forms local database

I am trying to implement a database following this: https://docs.microsoft.com/nl-nl/xamarin/xamarin-forms/app-fundamentals/databases

But I am getting an aggregate.exception on the main() function when debugging on my iphone.

I added this to my app.cs:

`
static ItemDatabase database;

    public static ItemDatabase Database
    {
        get
        {
            if (database == null)
            {
                database = new ItemDatabase(
                  Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "WaarStaatSQLite.db3"));
            }
            return database;
        }
    }`

Then this is the database class:
` public class ItemDatabase
{
readonly SQLiteAsyncConnection database;

    public ItemDatabase(string dbPath)
    {
        database = new SQLiteAsyncConnection(dbPath);
        database.CreateTableAsync<Item>().Wait(); // aggregate.exception probably from this line
        Debug.WriteLine("Created Database");
    }

    //get all items from db async
    public async Task<ObservableCollection<Item>> GetItemsAsync()
    {
        Debug.WriteLine("get items");
        var data = await database.Table<Item>().ToListAsync();
        Debug.WriteLine(data.ToString());
        if(data != null)
        {
            return new ObservableCollection<Item>(data);
        }
        else
        {
            return null;
        }

    }

    //get all items from db not async
    public async Task<ObservableCollection<Item>> GetItemsNotDoneAsync()
    {
        var data = await database.QueryAsync<Item>("SELECT * FROM [Item] WHERE [Done] = 0");
        return new ObservableCollection<Item>(data);
    }

    //get item from db with id
    public async Task<Item> GetItemAsync(int id)
    {
        return await database.Table<Item>().Where(i => i.ID == id).FirstOrDefaultAsync();
    }

    //save or update a single item
    public async Task<int> SaveItemAsync(Item item)
    {
        if (item.ID != 0)
        {
            return await database.UpdateAsync(item);
        }
        else
        {
            return await database.InsertAsync(item);
        }
    }

    //delete item in db
    public async Task<int> DeleteItemAsync(Item item)
    {
        return await database.DeleteAsync(item);
    }
}`

I then call this function in the MainPageViewModel:

public override async void OnNavigatedTo(INavigationParameters parameters) { var data = await App.Database.GetItemsAsync(); if (data != null) { Debug.WriteLine(data.ToString()); Items = data; } }

OnNavigatedTo is a prism function.
I first thought maybe the OnNavigatedTo function can't be async but I found a question only saying the OnNavigatedTo function could be async void.

So I did some debugging using breakpoints and print statements and I found that the code stops in the database constructor on the createTable line. Because the Debug.writeline is never executed. Using a breakpoint on that line didn't help because i couldn't step in on the function.
I don't know if I needs to implement something in the ios-project because the sample didn't include anything.

Any help implementing databases is appreciated.