A Follow-up. I had the mentioned problem with the demo fixed, but I am still unable to tell what the issue I'm having is. Here is the full error log. Please let me know if there's some simple fix I'm missing.
rmmz_managers.js:2030 TypeError: Cannot read property 'call' of undefined
at Window_DeckSkillType.makeCommandList (IsiahCGCDeckEditor.js:1812)
at Window_DeckSkillType.Window_Command.refresh (rmmz_windows.js:1559)
at Window_DeckSkillType.Window_Command.initialize (rmmz_windows.js:1452)
at Window_DeckSkillType.Window_SkillType.initialize (rmmz_windows.js:2285)
at Window_DeckSkillType.initialize (IsiahCGCDeckEditor.js:1804)
at new Window_DeckSkillType (IsiahCGCDeckEditor.js:1796)
at Scene_DeckEditor.createCardTypeWindow (IsiahCGCDeckEditor.js:1123)
at Scene_DeckEditor.create (IsiahCGCDeckEditor.js:694)
at Function.SceneManager.changeScene (rmmz_managers.js:2084)
at Function.SceneManager.updateMain (rmmz_managers.js:2056)