As per the issue description mentioned above, you are getting conversion failed error when trying to export pdf to word, is that correct?
As we have checked the account details using the email address you are logged into the forums, you have subscription for Export PDF.
Could you try converting pdf using a different browser and see if this makes any difference. Also, for testing purpose, please connect the computer to a different network environment like a guest wired/wireless network, or mobile hotspot and try converting the PDF.
You can also try converting the PDF file to Word on your mobile device, and see if the issue is reproducible.
You may also try troubleshooting steps given in following forum threads:
Could you try exporting document using a web browser at this link: https://cloud.acrobat.com/exportpdf and see if this makes any difference. Also, try converting the PDF file to Word on your mobile device and check if that works.