diff --git a/src/main/java/millions/App.java b/src/main/java/millions/App.java
index 107ec61..9b459b9 100644
--- a/src/main/java/millions/App.java
+++ b/src/main/java/millions/App.java
@@ -3,8 +3,10 @@
 import java.math.BigDecimal;
 import javafx.application.Application;
 import javafx.scene.Scene;
+import javafx.scene.control.Alert;
 import javafx.stage.Stage;
 import millions.controller.GameController;
+import millions.controller.fileIO.InvalidFormatException;
 import millions.view.GameView;
 import millions.view.StartView;
 
@@ -33,6 +35,14 @@ public void start(Stage stage) {
 
                 Scene gameScene = new Scene(gameView, 1920, 1080);
                 stage.setScene(gameScene);
+              } catch (InvalidFormatException e) {
+                Alert alert = new Alert(Alert.AlertType.ERROR);
+                alert.setTitle("Error");
+                alert.setHeaderText("Error with selected file");
+                alert.setContentText("Please control the format of the selected file");
+
+                alert.showAndWait();
+
               } catch (RuntimeException ex) {
                 System.err.println(ex);
                 System.exit(0);
diff --git a/src/main/java/millions/controller/GameController.java b/src/main/java/millions/controller/GameController.java
index 5638338..fe626bf 100644
--- a/src/main/java/millions/controller/GameController.java
+++ b/src/main/java/millions/controller/GameController.java
@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.stream.Collectors;
 import millions.controller.fileIO.CSVStockFileParser;
+import millions.controller.fileIO.InvalidFormatException;
 import millions.controller.fileIO.StockFileReader;
 import millions.model.Exchange;
 import millions.model.Player;
@@ -21,18 +22,22 @@ public void startGame(
     if (preRunWeeks < 0) {
       throw new IllegalArgumentException("Pre run weeks cannot be negative");
     }
+    try {
+      StockFileReader reader = new StockFileReader(stockFilePath);
+      List<String> lines = reader.readFile();
+      CSVStockFileParser parser = new CSVStockFileParser(lines);
 
-    StockFileReader reader = new StockFileReader(stockFilePath);
-    List<String> lines = reader.readFile();
-    CSVStockFileParser parser = new CSVStockFileParser(lines);
-    List<Stock> stocks = parser.parse();
+      List<Stock> stocks = parser.parse();
 
-    exchange = new Exchange("Exchange", stocks);
-    for (int i = 0; i < preRunWeeks; i++) {
-      exchange.advance();
-    }
+      exchange = new Exchange("Exchange", stocks);
+      for (int i = 0; i < preRunWeeks; i++) {
+        exchange.advance();
+      }
 
-    player = new Player(name, startingMoney);
+      player = new Player(name, startingMoney);
+    } catch(InvalidFormatException e) {
+      throw new InvalidFormatException(e.getMessage());
+    }
   }
 
   public Player getPlayer() {
diff --git a/src/main/java/millions/controller/fileIO/CSVStockFileParser.java b/src/main/java/millions/controller/fileIO/CSVStockFileParser.java
index e52ebf9..a1084ad 100644
--- a/src/main/java/millions/controller/fileIO/CSVStockFileParser.java
+++ b/src/main/java/millions/controller/fileIO/CSVStockFileParser.java
@@ -13,7 +13,7 @@ public CSVStockFileParser(List<String> lines) {
     if (verifyCSV(lines)) {
       this.lines = lines;
     } else {
-      // throw file format error
+      throw new InvalidFormatException("Incorrect format for CSV File");
     }
   }
 
diff --git a/src/main/java/millions/controller/fileIO/InvalidFormatException.java b/src/main/java/millions/controller/fileIO/InvalidFormatException.java
new file mode 100644
index 0000000..6883256
--- /dev/null
+++ b/src/main/java/millions/controller/fileIO/InvalidFormatException.java
@@ -0,0 +1,7 @@
+package millions.controller.fileIO;
+
+public class InvalidFormatException extends RuntimeException {
+  public InvalidFormatException(String message) {
+    super(message);
+  }
+}
diff --git a/src/test/java/millions/CSVStockFileParserTest.java b/src/test/java/millions/CSVStockFileParserTest.java
index 8cb459b..7683445 100644
--- a/src/test/java/millions/CSVStockFileParserTest.java
+++ b/src/test/java/millions/CSVStockFileParserTest.java
@@ -4,38 +4,33 @@
 import millions.controller.fileIO.StockFileReader;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.io.TempDir;
 
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
+import java.sql.Array;
+import java.util.ArrayList;
+import java.util.List;
+
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class CSVStockFileParserTest {
-  @TempDir
-  static Path tempDir;
 
-  static Path sharedFile;
+  static String exampleString;
 
   @BeforeAll
   public static void setUpTestFile() throws Exception {
-    sharedFile = Files.createFile(tempDir.resolve("file.csv"));
-    String string = "# Top 500 US Stocks by Market Cap\n";
-    string += "# Ticker,Name,Price\n";
-    string += "\n";
-    string += "NVDA,Nvidia,191.27\n";
-    string += "AAPL,Apple Inc.,276.43\n";
-    string += "MSFT,Microsoft,404.68\n";
-    Files.writeString(sharedFile, string);
+    exampleString = "# Top 500 US Stocks by Market Cap\n";
+    exampleString += "# Ticker,Name,Price\n";
+    exampleString += "\n";
+    exampleString += "NVDA,Nvidia,191.27\n";
+    exampleString += "AAPL,Apple Inc.,276.43\n";
+    exampleString += "MSFT,Microsoft,404.68\n";
   }
 
   @Test
   public void parseStockFileTest(){
-    StockFileReader stockFileReader = new StockFileReader(sharedFile);
+    List<String> testList = List.of(exampleString.split("\n"));
 
-    CSVStockFileParser parser = new CSVStockFileParser(stockFileReader.readFile());
+    CSVStockFileParser parser = new CSVStockFileParser(testList);
     assertEquals(3, parser.parse().size());
   }
 }