Can' t scroll to bottom UICollectionview

I'm having trouble to scrolling to bottom, I tried other solutions but with no success.

I'm using IGLiskit

Here's the error:

attempt to scroll to invalid index path

Here's the code:

    func initMessages() {
    DataService.call.retrieveMessages(roomID: room.id ?? "") { (success, error, messages) in
        if !success {
            print("error", error!.localizedDescription)
        } else {
            guard let messages = messages else {return}
            self.messages = messages                
            DispatchQueue.main.async {
                self.adapter.performUpdates(animated: true, completion: nil)
                let indexPath = IndexPath(item: self.messages.count - 1, section: 0)
                self.collectionView.scrollToItem(at: indexPath, at: .bottom, animated: true)
            }
        }
    }
}

do you have 2 sections in collectionview?, it this yes ignore my answer, i hope the problem is you are trying to acces a section 1, you just have the section 0 available, try to change this code:

func initMessages() {
    DataService.call.retrieveMessages(roomID: room.id ?? "") { (success, error, messages) in
        if !success {
            print("error", error!.localizedDescription)
        } else {
            guard let messages = messages else {return}
            self.messages = messages                
            DispatchQueue.main.async {
                self.adapter.performUpdates(animated: true, completion: nil)
                // Here in section
                let indexPath = IndexPath(item: self.messages.count - 1, section: 0)
                self.collectionView.scrollToItem(at: indexPath, at: .bottom, animated: true)
            }
        }
    }
}

EDIT: ok, if the section didn't work try this extension:

extension UICollectionView {
    func scrollToLast() {
        guard numberOfSections > 0 else {
            return
        }

        let lastSection = numberOfSections - 1

        guard numberOfItems(inSection: lastSection) > 0 else {
            return
        }

        let lastItemIndexPath = IndexPath(item: numberOfItems(inSection: lastSection) - 1,
                                          section: lastSection)
        scrollToItem(at: lastItemIndexPath, at: .bottom, animated: true)
    }
}

usage:

collectionView.scrollToLast()