Once a month it checks for subscription and you need internet connection once a month to verify the payment.
If there is no internet it will work till the date of payment renewal check.
Thanks for your quick reply. But this does not address my problem. I am aware that Creative Cloud needs to sign in once a month. However if I now sign out of Creative cloud and then try to run Lightroom CC, I get this message.
and if I then sign in, I get this message :
Thus it appears I have just been licensed when I have had a subscription for one month.
When you are finished working with Lightroom you do not need to "sign out" this will deactivate the application That will mean that you have to "Sign in" again if you wish to use the application.
From the menu bar , top left, click on Lightroom and select Quit Lightroom from the dropdown dialog.
Your license allow you two active installations of the application so you can "sign out" deactivate one and "sign in" activate on a different computer.
Thank you everyone for your replies. I understand. I was under the impression that continuing to be signed in to Creative Cloud would require my internet connection to be active. Obviously that is not the case. Problem solved.