Please never post your serial number on forums as it can be used by others.
The serial number is not for this version of Acrobat. Make sure you have installed the correct version.
If you need you can also Contact Customer Care . Sign in with your Adobe ID and select product from list.
Then select chat or phone under "Still need help?Contact us".
Let us know if you need any further help.
Regards,
Meenakshi