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CrashPlan Support

Unable To Back Up To CrashPlan Central

Applies to:
  • CrashPlan for Home
Need enterprise or small business documentation?
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 are unable to connect to CrashPlan Central, the status indicator for the destination on the Backup tab is typically grey instead of green. Additionally, you may see one of the following messages:

  • Disconnected, retrying in X
  • Unable to back up - no connection
  • Waiting for connection
  • Connecting to Backup Destination

Follow the troubleshooting steps in this article to identify and remedy the issue. For issues with connecting to a computer destination in the CrashPlan app, see Unable To Back Up To Another Computer.


  • If you are attempting to connect to CrashPlan Central from behind a proxy server, please review our configuration information.
  • Some businesses and schools configure their networks in a way that blocks connections to our cloud destination, CrashPlan Central (by blocking the required TCP port, 443). If your computer is on a network that blocks port 443, you won't be able to connect to the destination.
  • The error "Unable to connect to the backup engine" is usually not a network error. Typically when you see this error, you are unable to open the CrashPlan app. See our Unable to Connect to the Backup Engine article for further troubleshooting.

Recommended solution

Start by manually instructing the CrashPlan app to reconnect with the destination. This is an easy catch-all solution that can repair a disruption in the connection. Simply enter the restart command in the CrashPlan app's Command window:

  1. Open the CrashPlan app.
  2. Double-click the CrashPlan logo in the upper-right corner.
    The CrashPlan command-line area opens.
  3. Enter this command:
    ra, restart
  4. Press Enter.
    This closes the CrashPlan app, stops the CrashPlan service, and then restarts the CrashPlan service.

Reauthenticate using the CLI

Alternative solution

If your CrashPlan app cannot contact CrashPlan Central after restarting, follow these steps to verify that your computer can make a network connection to CrashPlan Central.

Step 1: Run telnet

  1. Open a command prompt on your computer. (On Windows or macOS High Sierra 10.13, you must turn on Telnet before you can use it.)
      • Windows:
        • Windows 10 and Windows 8: Start > All Apps > Windows System > Command Prompt
        • Windows 7: Start > All Programs > Accessories > Command Prompt
      • OS X: Applications > Utilities > Terminal
      • Linux: Open Terminal or another command prompt for your distribution.
  2. Enter the telnet command to test your connection to CrashPlan Central:
    telnet 443

Step 2: Read the telnet response

If your command prompt shows the following Connected message, your CrashPlan app can successfully connect to the Code42 cloud:

telnet 443
Connected to
Escape character is '^]'.

If your command prompt shows anything else, your CrashPlan app cannot connect to the Code42 cloud. Common failure messages include:

  • Connection refused
  • Operation timed out
  • Unable to connect to remote host
  • No response

Step 3: Troubleshoot a failed connection

If your Telnet test did not connect to the Code42 cloud, your issue is caused by your computer or network, not by the CrashPlan app. Check the following common causes of this issue:

  • Your router's network configuration or port forwarding settings
  • Other conflicting software on your computer, such as antivirus, security, or parental control software

If you cannot connect to CrashPlan Central after investigating these common causes, contact our Customer Champions.