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CrashPlan Support

Unable To Connect To The Backup Engine

Applies to:
  • CrashPlan for Home
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This article is intended for CrashPlan for Home users. For Code42 CrashPlan and CrashPlan for Small Business documentation, read this page on our enterprise support site.


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.

Under the hood

The CrashPlan app consists of two parts:

  • Graphical user interface that the user interacts with
  • CrashPlan service that runs in the background

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.

Unable To Connect To Backup Engine

Recommended solutions (all operating systems)

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.

Restart the CrashPlan service

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.

Out of memory

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.

Uninstall and reinstall

If you're still having trouble, the next step is to uninstall and reinstall the CrashPlan app.

Check for port conflicts

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.

Recommended solutions (Windows)

If the recommended solutions for all platforms didn't resolve the problem, try the following recommendations for Windows.

Verify that the CrashPlan service is enabled

You can verify that the CrashPlan service enabled from the Microsoft Services menu:

  1. Open the Start menu.
  2. Locate and open the Services program:
    • Windows 10: Click the Search box, type Services, and press enter.
    • Windows Vista, 7, & 8: Type services.msc into the Start menu search bar and press enter.
    • Windows XP: Select Run and type "services.msc", then press enter.
  3. Double-click CrashPlan Backup Service.
    The CrashPlan Backup Service Properties window opens.
  4. Ensure that the Startup Type is set to Automatic.
  5. If the Start service status button is available, click it to start the CrashPlan service.
  6. Click Apply if you made changes to your settings, then close the window.

Failure after restarting Windows

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:

  1. Open the CrashPlan Backup Service's properties window using the directions above.
  2. In the General tab, change Automatic to Automatic (delayed start).
  3. (Windows XP) If the Automatic (delayed start) option is unavailable, click the Recovery tab, and set First failure and Second failure to Restart the Service.
  4. Click OK.

Recommended solution (Linux)

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:

  1. Uninstall the CrashPlan app.
  2. Change the Linux system language to English.
    Consult the documentation for your Linux distribution for instructions on changing the system language.
  3. Install the CrashPlan app.
  4. Change the Linux system language back to your language.
    CrashPlan will open normally.

Alternate solution

Manually starting the CrashPlan service after rebooting your computer will allow you to open the CrashPlan app.

Starting The CrashPlan service
Using this method to start the CrashPlan service will not persist after restarting the computer and will have to be reapplied after every restart.