アップグレードできない

Hi Ayumik, 

We are sorry for the delay in responding to your query.

In order to edit a pdf file you need to have Acrobat DC subscription. We have checked your account and found that you are a subscriber of Adobe PDF Pack.

"Edit" feature doesn't come up with the PDF Pack subscription. You need to upgrade it to Acrobat DC-Plans and pricing | Adobe Acrobat DC 

Try following the steps suggested in the help article here: Learn how to change your Adobe Creative Cloud plan  and if that doesn't help, then you may contact our customer care- Contact Customer Care

Hope this answers your query.

Regards,

Akanchha