Sorry to hear you're having trouble with this too.
I've located your account and re-synced your subscriptions which has been know to help with this error.
Also, to give this the best chance of working, I'd like you to follow these steps for uninstalling/ reinstalling the app (I've already added a device change for this).
First I would like you to uninstall the app. Once you've done that, switch off your device and power it back on again. Then, On a PC or Laptop, go to anywhere.virginmedia.com > My Profile > Device Settings and delete the device from the 'My Registered Devices' section.
When that's done, return to your device and download the TV Anywhere app.
Once the app has downloaded, sign in using your primary account details. Go to the channel listings and select Channel 4 > Watch Now > Watch On Device. This should then prompt you to register the device.
Follow these instructions in this order and let me know how it goes.
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