I am having the same issue with boxsets on Virgin TV Go.
They were all working fine on Saturday, and then yesterday I am being asked to upgrade. Tried a few different boxesets from SkyOne, History and Syfy and all say the same thing. Rang Virgin today and after an hour they still couldn't work out the issue, and couldn't resolve due to being short on staff.
I have the full TV package and they work fine on the V6 Box, just not on Virgin TV Go. Tried Android tablet/Phone and also on a windows PC and still the same issue.
there are currently issues with TV Go which VM are aware of. If you click the Check service status at the top of this page you will see the latest update.
The message states
Customers using our TV Go service may have an issue streaming some channels and may get an Error message upgrade to watch. We are sorry about this, our engineers are looking at fixing this as soon as possible.
Different people are having differing issues, some are unable to login, some are unable to play boxsets etc
At the time of posting this the Fix estimate is 02 July12:00
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali