Any reason why the Xfinity TV app does not work on the Nexus Player?
the xFinity TV app is currently only offered on android/apple phones and tablets. If you acquire an android recent version device the app should work well.
What version of Android is the Nexus Player running? If Nougat, I've read some posts where people have had issues with the app crashing on their smartphone/tablet.
Also, since the Nexus Player is not a smartphone or tablet, it might fall under the "Unsupported Devices" category found on the XFINITY TV App Minimum System Requirements.
Has it ever worked for you?
The Nexus Player has the latest version of the software, but the Xfinity TV app keeps crashing when you try to open it.