During the rollout of CrashPlan app version 3.6.3, an issue was discovered affecting OS X 10.7.3 and earlier. Code42 chose to pause the upgrade and resolve this issue before pushing the upgrade for all users. Unfortunately, this introduced extra time to our intended rollout window.
Pausing the upgrade created an unintended situation: computer-to-computer backups are prevented when the CrashPlan app version numbers are mismatched. We have documentation on what to do if you find yourself in this situation here.
Please Note: The issue above is with the upgrade only. The 3.6.3 installer and client are unaffected.