Hi Cdherda,
As per the above mentioned description, when trying to export pdf, you are getting a message to purchase Export pdf whereas you already have a subscription, is this correct?
Please try following troubleshooting steps:
1- Launch Reader > click Edit > Preferences > under Security ( Enhanced) > uncheck the box Enable Protected Mode at startup.
2- Click OK and try again.
Please note: Disabling protected mode is for troubleshooting purposes only. Turn the feature back on when troubleshooting is complete.
Also, check for the unsupported configuration here: Protected Mode troubleshooting | Adobe Reader
You can also use Export PDF services online using a web browser @ https://cloud.acrobat.com/exportpdf
Could you please let us know the operating system installed on the machine?
What is the version of Reader you have on the machine? You may refer to this on how to: Identify the product and its version for Acrobat and Reader DC
Keep us posted with the results.
Shivam