In most cases, Creative Cloud downloads and installs the update automatically when you sign in. If you're unable to sign in from the Creative Cloud application, then do the following:
You can safely delete the ACC.log file from your computer.
To do so, navigate to one of the following folders and delete the acc.log files:
Note: Some files and folders are hidden on Windows. See Show hidden files, folders, filename extensions | Windows XP, Vista, Windows 7, 8 for more information.
Note: The user Library folder is hidden on Mac OS 10.7 and later. See Access hidden user library files | Mac OS 10.7 and later for more information.