Adobe Acrobat Pro 2020 (PC) 2 Devices - the key seems to be revoked

G2a seem to have a very controversial reputation, with some people suggesting their site includes stolen software codes, that are likely to be blocked, and real codes paid for with stolen cards, ditto.  For sure they are not an authorised Adobe reseller, and Adobe also block unauthorised resellers if they track them down.  This might work for a game you plan to use for a few weeks, but hardly for an office app. 

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post if it helps you get responses.

<moved from using the community>

when a serial number is revoked, you only find out when trying to reinstall and reuse the serial number.  you can check with adobe support and ask why the serial number was revoked and when it was revoked.  (and you may find the revocation was erroneous.)

there are 3 ways to contact adobe; chat, phone and twitter:

chat:
use a browser that allows popups and cookies, and click here, https://helpx.adobe.com/contact.html?rghtup=autoOpen
in the chat field (lower right), type AGENT
be patient, it can take quite a while to reach a human.

phone:
https://helpx.adobe.com/contact/phone.html

twitter:
tweet @AdobeCare

p.s. if you're contacted by anyone (via email or private message), it's much more likely to be a scammer than an adobe representative. ie, double check for an employee badge if contacted in the forums and look for an adobe.com domain in the email address if you click reply to an email. then check again and be very suspicious. any other method of contacting (or offering to contact you) is almost certainly a scam, https://community.adobe.com/t5/using-the-community-discussions/staying-safe-in-the-adobe-support-community/td-p/12919684/redirect_from_archived_page/true