All, I had this same issue and just got it resolved.
Keep in mind that your mobile device/DirecTV app can access your DVR via Wifi or cell network, so this Cannot Retrieve Your List of Receivers cannot be an issue with your own network. The app actually communicates with your DVR via satellite through DirecTV's center. You will also note that recording to your DVR via the directv.com website (under Guide) also fails, further verifying this assertion.
I called DirecTV and requested Tier 4 support. Within seconds he immediately found the problem. On rare occasions during an installation, the DVR does not communicate with DirecTV's database. So, although you have a full-functioning DVR in your house, it shows up as a regular receiver on their end. It took 5 minutes for them to update the database with my Genie/DVR and then reset my device remotely. Once it came back online and they remotely reconfigured the menus, I logged out of the app and directv.com and re-logged in. I was able to launch the app and my directv.com account via a web browser and both show my DVR correctly and I was able to record without issue.
Hope this helps someone!
