There are a few potential causes of a credit score dropping after an account is removed from your credit file. One reason could be that you may have been reported to the credit bureau for unpaid debts. If this is the case, your credit score could drop as a result. Additionally, if you have had any recent financial problems, they could also affect your credit score. Finally, if you have been using your account for illegal activities or if you have been in default on any payments, those factors could also impact your credit score.