Can you please fix the item set

I've been playing a lot of Morgana support recently and the suggested items are always for mid so I decided to make a custom item set for Morgana. But when I try to click and drag an item into one of the slots it doesn't drag. Quite frankly I'm getting rather annoyed because it hasn't been fixed for awhile, so riot can you please fix that I know your busy but it would make me and probably many others quite happy. Thank you in advance