Downgrading to Adobe Acrobat 9 Pro

Good afternoon,

Rupesh direct us from Adobe Customer Serivce, as per case number: 0187709220

We have uninstalled Adobe Acrobat DC and have installed Adobe Acrobat 9 Pro but are having problems with the activating the available license we have <serial number removed> as it states that it is an upgrade license.

Would you please indicate if we may use this license as it is currently free and we have actually downgraded rather than upgraded in this particular case.

The error message, "The serial number you entered indicates that your setup is for an upgrade version of Adobe Acrobat Pro. To be eligible for this upgrade, you must already own qualifying product. We looked in the default locations where the qualifying products installed on this machine but none were found. You may verify upgrade eligibility without installing your previous software by completing the fields below"

and then it asks for us to pick from a drop down of old Adobe Acrobat versions and their serial numbers

We had tried to enter serial numbers from older Adobe Acrobat products that we have here but it wouldn't accept it.

probably because the previously installed version was actually an upgrade from this version (ie. DC to 9 Pro)