diff --git a/0-Plugin/src/main/java/cli/Subcommand.java b/0-Plugin/src/main/java/cli/Subcommand.java
index ecf187b..c8ae3df 100644
--- a/0-Plugin/src/main/java/cli/Subcommand.java
+++ b/0-Plugin/src/main/java/cli/Subcommand.java
@@ -18,7 +18,7 @@ abstract public class Subcommand {
 	public String executeSubcommand(String[] args) {
 
 		try {
-			commandExits(args[0]);
+			commandExists(args[0]);
 			return commands.get(args[0]).apply(args);
 		}
 		catch (IndexOutOfBoundsException e) {
@@ -26,7 +26,7 @@ abstract public class Subcommand {
 		}
 	}
 
-	private void commandExits(String command) {
+	private void commandExists(String command) {
 		if (commands.get(command) == null) {
 			throw new CliError("Subcommand " + command + " does not exist! " + getUsage());
 		}
diff --git a/0-Plugin/src/main/java/main/Main.java b/0-Plugin/src/main/java/main/Main.java
index 3fab6c5..6eb467c 100644
--- a/0-Plugin/src/main/java/main/Main.java
+++ b/0-Plugin/src/main/java/main/Main.java
@@ -1,20 +1,24 @@
 package main;
 
-import persistence.GenericCSVDAO;
-import persistence.category.CSVCategoryPersistenceAdapter;
-import persistence.category.CategoryEntity;
-import tag.TagName;
-
-import java.io.File;
+import persistence.PersistenceError;
 
 public class Main {
 
 	public static void main(String[] args) {
 
-
 		CommandHandler commandHandler = new CommandHandler();
 
-		commandHandler.executeCommand(args);
+		try {
+			commandHandler.executeCommand(args);
+		}
+		catch (PersistenceError persistenceError) {
+
+			System.out.println("There was a Error with loading or saving the persistence data.");
+			System.out.println(persistenceError.getMessage());
+		}
+		catch (RuntimeException runtimeException) {
+			System.out.println(runtimeException.getMessage());
+		}
 
 	}
 }
diff --git a/0-Plugin/src/test/java/persistence/GenericCSVDAOTest.java b/0-Plugin/src/test/java/persistence/GenericCSVDAOTest.java
index 80e7676..4ed35ff 100644
--- a/0-Plugin/src/test/java/persistence/GenericCSVDAOTest.java
+++ b/0-Plugin/src/test/java/persistence/GenericCSVDAOTest.java
@@ -13,7 +13,10 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 class GenericCSVDAOTest {
 
 	GenericCSVDAO<CategoryEntity> sut;
-	File file = new File("test.csv");
+	File file = File.createTempFile("test","link-ditch");
+
+	GenericCSVDAOTest() throws IOException {
+	}
 
 	@BeforeEach
 	public void beforeEach() throws IOException {
@@ -35,8 +38,7 @@ class GenericCSVDAOTest {
 	public void addWorks() throws IOException {
 		assertEquals(0, sut.getALl().size());
 
-		var entityToAdd = new CategoryEntity("categoryName", 99);
-		sut.add(entityToAdd);
+		CategoryEntity entityToAdd = addDummyEntity("categoryName", 99);
 		var foundEntity = sut.getALl().stream().findFirst().orElseThrow();
 
 		assertEquals(entityToAdd, foundEntity);
@@ -44,23 +46,27 @@ class GenericCSVDAOTest {
 
 	@Test
 	public void removeWorks() throws IOException {
-		var entityToAdd = new CategoryEntity("categoryName", 99);
-		sut.add(entityToAdd);
+		CategoryEntity entityToAdd = addDummyEntity("categoryName", 99);
 
 		sut.remove(entityToAdd);
 
 		assertEquals(0, sut.getALl().size());
 	}
 
+
 	@Test
 	public void removeAllWorks() throws IOException {
-		var entityToAdd1 = new CategoryEntity("categoryName1", 101);
-		sut.add(entityToAdd1);
-		var entityToAdd2 = new CategoryEntity("categoryName2", 102);
-		sut.add(entityToAdd2);
+		addDummyEntity("categoryName1", 101);
+		addDummyEntity("categoryName2", 102);
 		assertEquals(2, sut.getALl().size());
 		sut.removeAll();
 
 		assertEquals(0, sut.getALl().size());
 	}
+
+	private CategoryEntity addDummyEntity(String categoryName, int id) {
+		var entityToAdd = new CategoryEntity(categoryName, id);
+		sut.add(entityToAdd);
+		return entityToAdd;
+	}
 }
diff --git a/2-Application/src/main/java/link/LinkUseCase.java b/2-Application/src/main/java/link/LinkUseCase.java
index 282c3cf..ec4bcdf 100644
--- a/2-Application/src/main/java/link/LinkUseCase.java
+++ b/2-Application/src/main/java/link/LinkUseCase.java
@@ -18,12 +18,12 @@ public class LinkUseCase {
 	private final LinkRepository linkRepository;
 	private final CategoryRepository categoryRepository;
 	private final TaggingUseCase taggingUseCase;
-	private final LinkIdGenerator linkIdGenerator;
+	private final RandomLinkIdGenerator linkIdGenerator;
 
 	public LinkUseCase(LinkRepository linkRepository,
 	                   CategoryRepository categoryRepository,
 	                   TaggingUseCase taggingUseCase,
-	                   LinkIdGenerator linkIdGenerator) {
+	                   RandomLinkIdGenerator linkIdGenerator) {
 		this.linkRepository = linkRepository;
 		this.categoryRepository = categoryRepository;
 		this.taggingUseCase = taggingUseCase;
diff --git a/2-Application/src/main/java/tag/TaggingUseCase.java b/2-Application/src/main/java/tag/TaggingUseCase.java
index eaa18d0..40637ed 100644
--- a/2-Application/src/main/java/tag/TaggingUseCase.java
+++ b/2-Application/src/main/java/tag/TaggingUseCase.java
@@ -19,5 +19,4 @@ public class TaggingUseCase {
 		tagMatcherRepository.getTagMatchers().forEach(tagMatcher -> tagMatcher.ifMatches(url).addTo(result));
 		return result;
 	}
-
 }