We apologize for the inconvenience caused, as per the description above, you are not able to use Adobe ExportPDF service as it asking you to resubscribe when you convert a PDF to Word, Is that correct?
The record shows that you are subscribed to Adobe ExportPDF service on your current Adobe ID, please access the service through the URL https://cloud.acrobat.com/exportpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari.
If you are using the freeware Adobe Reader DC and getting the error message, please sign out and sign back in Adobe Reader with your Adobe ID and password, 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.