we are facing always the same issue when trying to run the Acrobat Reader DC:
We have a montly subcription for Adobe Acrobat Reader DC. But when opening a pdf, it is opened with the reader and tells me I have to subscribe to Acrobat Reader DC in order use the extra features. Then it guides me to the subscription only until I click on any of the options, it will tell me "you already have a subcription". Well, then I am stuck as the reader does not realize that and thus I cannot use any Pro features.
By chance we manage to open it "in the right way" after a while wasting 10-20min. We see no clear logic how to get the Pro version running.
Furthermore, despite what some may tell you, you really should not have both Acrobat Reader and Acrobat Pro installed in parallel on a single system. Acrobat Pro is a superset of Acrobat Reader. There is nothing to be accomplished by having both on a system.
Uninstall Reader and download and install Acrobat Pro.