This is not too tricky fellas.
MJ8 will work as a basic player forever for free. There is however a feature set (most of the really funky stuff) will cease functioning after 30 days
Historically, you bought V6, you got unlimited use of V6. AND, you also got unlimited use of V7.
IE: one total upgrade, free. Buy one, get the next one free.
Good deal.
Irritated - if you uninstall V7 completely, clean the registry, reboot and reinstall V7, it will work ad infinatum.
Yes, yes, I know, you shouldn't have to clean the registry, I hear you. Just do it.
Why? Because it will solve your problem I guarantee it - well not quite. But if it doesn't then something must be changed in your configuration, some driver corrupted, some MS thing cocked up, problem your end - that much is certain.
Sorry, that this is not what you want to hear, and sorry also to sound unsympathetic, but really your could have saved yourself 50 bucks worth of grief and anguish, and got yourself a barrow full of excellent new features if you had just done the 25 buck upgrade.
Yes, yes, I know, you shouldn't have to upgrade, I hear you. And you don't have to - unless you want to do yourself a favour.
PS: I am in no way associated with JRiver.