Can't get iCloud metadataQuery to work

Question

I have an issue with the iCloud metadataQuery.

I am trying to fetch some documents from iCloud but when I call the NSPredicate function I get the following error in the console of Xcode:

warning: could not load any Objective-C class information from the dyld shared cache. This will significantly reduce the quality of type information available.

Note: I am using Swift version 2.

This is my function:

var _iCloudQuery:NSMetadataQuery!
    func iCloudQuery()->NSMetadataQuery?{

        if (_iCloudQuery == nil) {
        _iCloudQuery = NSMetadataQuery.init()
        _iCloudQuery.searchScopes = [NSMetadataQueryUbiquitousDocumentsScope]
        _iCloudQuery.predicate = NSPredicate(format: "(%K = '*')", NSMetadataItemURLKey)//
        // Set observer here
            NSNotificationCenter.defaultCenter().addObserver(self, selector: "processCloudQueryResults:", name: NSMetadataQueryDidFinishGatheringNotification, object: _iCloudQuery)
            NSNotificationCenter.defaultCenter().addObserver(self, selector: "processCloudQueryResults:", name: NSMetadataQueryDidUpdateNotification, object: _iCloudQuery)



        }

        return _iCloudQuery
    }

I already figured out that processCloudQueryResults never gets fired because there are no items in icloudQuery but still there are documents in my iCloud container so there should.

This is a related topic with no solutions:

Searching for files using NSMetadataQuery does simply nothing