During the release of CrashPlan 3.6.3, an issue was identified with the Windows 3.6.3 app installer that prevents CrashPlan from automatically upgrading to a newer version. This installer was available from February 12th to February 19th, 2014.
This does not impact your ability to back up or restore. Nor is the functionality of the application negatively impacted.
We released a subsequent build of this installer, which is able to receive automatic upgrades, to our downloads page on February 20th 2014.
If you are affected by this issue, you will see the history log repeating the message "Downloading a new version of CrashPlan."
To resolve this issue, or to learn more, please see this article.