I write a empty class for deinit test class MyEmptyModel { deinit { print("MyEmptyModel deinit") } } Every tab in CPTabBarTemplate must be visited at least once, after which deinit is called. so it can cause memory issue if user doesn't visit all tabs. I think it's a bug. here's a code I wrote for test. is there any code wrong? // create first tab list template let firstItem = CPListItem(text: "firstItem", detailText: "hoho") firstItem.handler = { _, completion in let firstInnerItem = CPListItem(text: "firstInnerItem", detailText: "haha") firstInnerItem.handler = { _, completion in print("firstInnerItem!!") completion() } firstInnerItem.userInfo = MyEmptyModel() let firstInnerSection = CPListSection(items: [firstInnerItem]) let firstInnerList = CPListTemplate(title: "First Inner", sections: [firstInnerSection]) firstInnerList.emptyViewTitleVariants = ["First Inner empty"] interfaceController.pushTemplate(firstInnerList, animated: true) { _, _ in completion() } } let firstSection = CPListSection(items: [firstItem]) let firstList = CPListTemplate(title: "First", sections: [firstSection]) // create second tab list template let secondItem = CPListItem(text: "secondItem", detailText: "hoho2") secondItem.handler = { _, completion in let secondInnerItem = CPListItem(text: "secondInnerItem", detailText: "haha2") secondInnerItem.handler = { _, completion in print("secondInnerItem!!") completion() } secondInnerItem.userInfo = MyEmptyModel() let secondInnerSection = CPListSection(items: [secondInnerItem]) let secondInnerList = CPListTemplate(title: "Second Inner", sections: [secondInnerSection]) secondInnerList.emptyViewTitleVariants = ["Second Inner empty"] interfaceController.pushTemplate(secondInnerList, animated: true) { _, _ in completion() } } let secondSection = CPListSection(items: [secondItem]) let secondList = CPListTemplate(title: "Second", sections: [secondSection]) // create third tab list template let thirdItem = CPListItem(text: "thirdItem", detailText: "hoho3") thirdItem.handler = { _, completion in let thrdInnerItem = CPListItem(text: "thirdInnerItem", detailText: "haha3") thrdInnerItem.handler = { _, completion in print("thirdInnerItem!!") completion() } thrdInnerItem.userInfo = MyEmptyModel() let thirdInnerSection = CPListSection(items: [thrdInnerItem]) let thirdInnerList = CPListTemplate(title: "Third Inner", sections: [thirdInnerSection]) thirdInnerList.emptyViewTitleVariants = ["Third Inner empty"] interfaceController.pushTemplate(thirdInnerList, animated: true) { _, _ in completion() } } let thirdSection = CPListSection(items: [thirdItem]) let thirdList = CPListTemplate(title: "Third", sections: [thirdSection]) // create tabbar template and set to root template var tabBarTemplates = [CPTemplate]() tabBarTemplates.append(firstList) tabBarTemplates.append(secondList) tabBarTemplates.append(thirdList) let tabBarTemplate = CPTabBarTemplate(templates: tabBarTemplates) interfaceController.setRootTemplate(tabBarTemplate, animated: false) { _, _ in }