RPG Maker MV 1.6.0 - Scene Item Game Breaking Code (Patreon)

For those wondering about why plugins that use Scene Item is broken as of the 1.6.0 update, it's because they added a new function to it:

Scene_Item.prototype.update = function() {
   Scene_ItemBase.prototype.update.call(this);
   if (this._categoryWindow.active !== true && this._itemWindow.active !== true && this._actorWindow.active !== true) {
       this._categoryWindow.activate();
   }
};

This function makes it if the category, item, and actor windows aren't all active at once, it will force the category window to become active. Naturally, this does not take into consideration what plugins are installed, and especially not the plugins that add new windows to the item scene. This means that if you are using an item upgrade window in your Scene Item, the moment that activates and the other three windows are deactivated, the category window will activate itself and take multiple priority over the other non-three window functions. Destructive code at its best.

Fear not, the YEP_CoreEngine.js update I'll be releasing sooner or later will suppress this poorly thought out function in order to let everybody's customized item scenes work again.