I'm running iMac late 2015 edition, please help!
Which version of Lightroom?
If Cloud, read below
Log out of your Cloud account... Restart your computer... Log in to your paid Cloud account
-If you have more than one email, but sure you are using the one linked to your subscription
-Sign in help http://helpx.adobe.com/x-productkb/policy-pricing/account-password-sign-faq.html
Moving to Photoshop Lightroom
Retrieving data ...