SKProductsRequest crashes Mac OS X

xCode 7.3, Mac OSX 10.11.4

    self.productsRequest= [[SKProductsRequest alloc] initWithProductIdentifiers: [NSSet setWithObject: self.productIdentifier]];
    self.productsRequest.delegate = self;
    [self.productsRequest start];

I have enabled my app for In app purchases. I have added a product in ITunes Connect. This particular class is defined as:

NSObject <SKRequestDelegate, SKProductsRequestDelegate>

And it has the methods:

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response

- (void)requestDidFinish:(SKRequest *)request

- (void)request:(SKRequest *)request didFailWithError:(NSError *)error

I have the valid product Identifer set to the correct string identifying the product.

When I run the code, it either hangs or it crashes. None of the delegate methods are called.