If you attempt to start the CrashPlan app and it gets stuck on the CrashPlan splash screen displaying the error, "Unable to connect to backup engine, retry?", this article can help troubleshoot the issue. This error usually occurs because the CrashPlan service is not running.
The CrashPlan app consists of two parts:
These two pieces communicate over a local network connection that is built into every computer. When the CrashPlan app starts, the graphical user interface and CrashPlan service attempt to connect to each other. If they can't connect, the graphical user interface won't start.
The recommendations below apply to all operating systems. These are the resolutions that most often resolve the issue. If these solutions don't resolve the issue, review additional recommendations for your specific operating system below.
The first thing to try on all platforms is to restart the CrashPlan service. If this doesn't resolve the issue, try the recommended solutions below.
If you have a large backup selection (more than 1 TB or 1 million files), you may need to allocate more memory to the CrashPlan app. When CrashPlan runs into this memory limit, the CrashPlan service is not able to run, resulting in the "Unable to connect to backup engine" message. If you have a large file selection backing up, refer to our troubleshooting article on this topic to address the issue.
If you're still having trouble, the next step is to uninstall and reinstall the CrashPlan app.
If the CrashPlan service still does not connect, verify that another application is not already using the required ports. While CrashPlan may not require these ports all of the time, the CrashPlan service still must prepare them for use.
If the recommended solutions for all platforms didn't resolve the problem, try the following recommendations for OS X.
There is a known issue in the 3.6.3 version of the CrashPlan app that impacts systems running Mac OS X with case-sensitive file systems. This issue results in the Unable to connect to the backup engine message upon opening the CrashPlan app. See our troubleshooting guide for to resolve the issue.
The CrashPlan app version 3.4.1 and earlier is not compatible with Java 1.7. On October 16, 2012, Apple released an update to Java 1.6 that could cause your computer to use Java 1.7 by default. This WikiHow article can help you determine which version(s) of Java are installed on your computer.
If the recommended solutions for all platforms didn't resolve the problem, try the following recommendations for Windows.
You can verify that the CrashPlan service enabled from the Microsoft Services menu:
If the "Unable to connect to backup engine" error returns after each reboot, this is usually caused by a Windows service causing a loopback conflict with the CrashPlan service at boot. To resolve this, you can delay CrashPlan's startup:
If your system language is not set to English when the CrashPlan app is installed, the application starts and backs up but fails to open after rebooting the computer. To ensure that the CrashPlan app is able to open after rebooting:
Manually starting the CrashPlan service after rebooting your computer will allow you to open the CrashPlan app.