We're sorry for the delayed response and inconvenience caused. As per the description above, you are not above to use the Adobe ExportPDF service, Is that correct?
The record shows that you are subscribed to Adobe ExportPDF service, try exporting the PDF through the URL https://cloud.acrobat.com/exportpdf 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 freeware Adobe Reader desktop application and getting the error message, please sign out from Adobe Reader, reboot the machine, sign back in Adobe Reader and check for any pending updates of Adobe Reader from help>check for updates, reboot the machine after updating Adobe Reader and try exporting the PDF file.
For more troubleshooting, you can refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud...
Let us know how it goes and share your observation.
Thank you for your response. However the link provided (https://cloud.acrobat.com/exportpdf) asks me to subscribe even though I already have a subscription and logged in using my existing account details. Am I meant to subscribe again. If so should I cancel my existing subscription before doing so.
We're sorry for the trouble you had, I have checked the records with your current Adobe ID(email) and found that the Adobe ExportPDF service and Acrobat Pro DC subscription is already canceled and inactive and this is the reason the above URL is re-directing you to a purchase page.
To check the plan details, please log in to Adobe.com>Manage Account>Plans and Products and check the plan details. You can also refer to Account and membership help
If you want to use the services, you have to resubscribe to Acrobat or Adobe ExportPDF services. For pricing details, you can refer to Plans and pricing | Adobe Acrobat DC
Feel free to update this discussion for any further assistance.