What is the creamy brown mould rotting my flowers?
Unfortunately this will usually be Botrytis or Grey mould. Keeping your growroom humidity down to a reasonable level during flowering, and using air movers will help to avoid this problem. But most gardeners will experience it at some point or another and will learn to deal with it by being extra vigilante in the last few weeks of flowering and or using suitable fungicides to help keep it under control.