diff --git a/VocabularyTrainer.xcodeproj/project.pbxproj b/VocabularyTrainer.xcodeproj/project.pbxproj
index 89ced17..9cc70b4 100644
--- a/VocabularyTrainer.xcodeproj/project.pbxproj
+++ b/VocabularyTrainer.xcodeproj/project.pbxproj
@@ -771,7 +771,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.3.1;
+				MARKETING_VERSION = 1.5.0;
 				PRODUCT_BUNDLE_IDENTIFIER = st.mic.VocabularyTrainer;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
@@ -795,7 +795,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.3.1;
+				MARKETING_VERSION = 1.5.0;
 				PRODUCT_BUNDLE_IDENTIFIER = st.mic.VocabularyTrainer;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
diff --git a/VocabularyTrainer/Home Screen/ViewController/HomeViewController.swift b/VocabularyTrainer/Home Screen/ViewController/HomeViewController.swift
index 2a79d3e..2cbca28 100644
--- a/VocabularyTrainer/Home Screen/ViewController/HomeViewController.swift	
+++ b/VocabularyTrainer/Home Screen/ViewController/HomeViewController.swift	
@@ -67,7 +67,7 @@ final class HomeViewController: UIViewController {
         return collectionView
     }()
     /// Data source of `collectionView`.
-    lazy var datasource: UICollectionViewDiffableDataSource<Int, LanguageCellViewModel> = { [weak self] in
+    lazy var datasource: UICollectionViewDiffableDataSource<Int, LanguageCellViewModel> = { [self] in
         let cellConfig = UICollectionView.CellRegistration<CollectionViewCell, LanguageCellViewModel> { cell, _, item in
             cell.configure(with: item)
         }
diff --git a/VocabularyTrainer/Training/View/TrainingView.swift b/VocabularyTrainer/Training/View/TrainingView.swift
index 0e87c56..76d47ec 100644
--- a/VocabularyTrainer/Training/View/TrainingView.swift
+++ b/VocabularyTrainer/Training/View/TrainingView.swift
@@ -260,6 +260,7 @@ final class TrainingView: UIView {
         } else {
             progresses[key] = 1.0
         }
+		guard let selectedLanguage = selectedLanguage else { return }
         UserDefaults.standard.set(progresses, forKey: "\(selectedLanguage)Progress")
     }