Sorry for the delay in response.
I have checked that you have Adobe Export PDF subscription.
It is an online service that helps you to convert the PDF to other formats files. You can also use this service through Adobe Acrobat Reader desktop or mobile application.
As you are experiencing an issue in exporting PDF to a Word file, try once to export the file online here https://cloud.acrobat.com/exportpdf.
Once you open the link, sign in with your Adobe ID that you have used to purchase the subscription.
Then go to Export PDF and upload the required file.
Check if the files convert without any issue.
Please make sure that the application is updated to the latest patch available.
To check the latest updates, you may refer this link Release Notes | Adobe Acrobat, Reader
If there is an update pending, launch the application and go to Help > Check for updates.
As you have mentioned that you receive an error message, can you share the exact error message?
Did you try to export other files to check if it is an issue with a particular file? If not, please try.
Let us know if you still need help with the issue.