diff --git a/ConfigEditor/MainForm.cs b/ConfigEditor/MainForm.cs
index f5f4b08..2ea3b0b 100644
--- a/ConfigEditor/MainForm.cs
+++ b/ConfigEditor/MainForm.cs
@@ -65,17 +65,20 @@ namespace ConfigEditor
 
         private bool CheckChanges()
         {
-            if (richTextBox1.Text != File.ReadAllText(opened_file))
+            if (opened_file != null)
             {
-                DialogResult result = MessageBox.Show("The document has been modified.\nDo you want to save your changes?", "Question", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Question);
-                if (result == DialogResult.Yes)
+                if (richTextBox1.Text != File.ReadAllText(opened_file))
                 {
-                    File.WriteAllText(opened_file, richTextBox1.Text);
-                    MessageBox.Show("File successfully saved.", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
-                    return true;
+                    DialogResult result = MessageBox.Show("The document has been modified.\nDo you want to save your changes?", "Question", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Question);
+                    if (result == DialogResult.Yes)
+                    {
+                        File.WriteAllText(opened_file, richTextBox1.Text);
+                        MessageBox.Show("File successfully saved.", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
+                        return true;
+                    }
+                    else if (result == DialogResult.Cancel)
+                        return false;
                 }
-                else if (result == DialogResult.Cancel)
-                    return false;
             }
             return true;
         }