Operator '==' cannot be applied to operands of type 'byte[]' and 'string'

I'm making a program with a login page and this error came up when coding it: Operator == cannot be applied to operands of type byte[] and string

Im not sure where to go with it or how to handle it. This is my section with the error:

private void button1_Click(object sender, EventArgs e)
{
    if (string.IsNullOrEmpty(textBox1.Text))
    {
        MessageBox.Show("Please Enter your username.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        textBox1.Focus();
        return;
    }
    try
    {
        using (DataEntities test = new DataEntities())
        {
            var query = from o in test.Users
                        where o.Username == textBox1.Text && o.Password == textBox2.Text
                        select o;
            if(query.SingleOrDefault() != null)
            {
                MessageBox.Show("You have been successfully logged in.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    //Add your code process login here
            }
            else
            {
                MessageBox.Show("Your username or password is incorrect.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

Thanks in advance!