We apologize for the inconvenience caused, as per the description above, you are not able to convert a PDF file as it's directing you to repurchase the Adobe PDFPack subscription, Is that correct?
The record shows that you are subscribed to Adobe PDFPack services on your current Adobe ID, please use the service through the URL https://cloud.acrobat.com/convertpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari and see if this brings any difference.
If you are using the free desktop version of Adobe Reader and getting the subscribe page while converting a PDF, please sign out and sign back in with your current Adobe ID and password in Adobe Reader, and check for any pending updates from help>check for updates. Reboot the machine and try exporting the PDF.
For more troubleshooting, you may refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud...
Feel free to update this discussion for any further assistance.