I've been playing a game as the Hansa in HTTT, with the ultimate objective of forming Prussia, making sure to satisfy the requirements spelled out here. I collected all the appropriate cores, culture-switched to Prussian ~1510, and waited for the Reformation to pop; that finally rolled around in 1516. The problem is, despite my having satisfied all the criteria, the decision isn't appearing in my decisions list! Is there anything else that must be done to make it show up? I own/have cored Danzig, Warmia, and Ostpreussen, both the Protestant and Reformed religions have appeared (though I am still Catholic), Prussia doesn't exist elsewhere, and I've been at peace for the last ten or fifteen years.