When you say you have paid access to UK-TV Play, do you mean through UK-TV directly? If so, that's nothing to with the (UK-TV branded) Virgin OnDemand services which depend on your VM-TV subscription.
Can you view any OnDemand programmes ok, as you may have a problem with you OnDemand in general? If you're not sure, pick a programme from ITV, C4 or C5 from the past couple of days, and see if it'll play ok.
If you can't view those programmes, then post back with some more details of what happens (including any error messages) and I'm sure we can help on here. If those programmes don't work, it would suggest that your TV subscription doesn't include the programme you're trying to watch. Again, post some details including what TV package you're on (which you can check using your my-Virgin Media online account) and I'm sure we can assist further.
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