Which OS are you using? Please specify the exact error message. As you open any of the CC app's on the same trial screen you might see an option to "License this software". Click on it and sign in with your Adobe Id associated with the subscription to activate. Refer the article: http://helpx.adobe.com/creative-cloud/kb/ccm-prompt-serial-number.html in case of further issues.
Thanks but I have no trouble getting on line. Have previously downloaded a trial software package, but then deinstalled. Now signed upto creative cloud, but it won't load - keeps finding the trial software. I've uninstalled all versions of indesign and just reinstalling.
The screen is sign in required for trial software, but does not allow me to enter any password - won't connect to the internet. OS is 10.9.2.