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This article applies to version 6.

Available in:

Small Business
Code42 Support

Connect to CrashPlan PRO Online

This article applies to version 6.

Available in:

Small Business


If you are unable to connect to CrashPlan PRO Online, the status indicator for the destination on the device details screen 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.


  • If you are attempting to connect to CrashPlan PRO Online from behind a proxy server, please review our configuration information.
  • Some businesses and schools block TCP port 443, which is required for connection to our cloud destination, CrashPlan PRO Online. Verify port 443 is not blocked.
  • 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 Code42 app. See our Cannot connect to background service article for further troubleshooting.

Recommended solution

You can identify and solve network connectivity problems through the process of elimination, shown below. For best results, follow the steps in the order presented.

Record your results
Record the results of each step below. If you are still unable to resolve the issue after completing each step, send this information to our Customer Champion team, along with logs from the Code42 app, to help them identify the problem as quickly as possible.

Step 1: Manually attempt to reconnect

Start by manually instructing the Code42 app to reconnect with the destination. This can repair a disruption in the connection. Enter the restart command in the Code42 app's Command window:

  1. Open the Code42 app.
  2. If necessary, sign in to your account.
  3. Use the keyboard shortcut for your operating system:
    • Windows: Ctrl+Shift+C
    • Mac: Option+Command+C
    • Linux: Ctrl+Shift+C
      The command-line area opens.
  4. Enter this command:
  5. Press Enter.
    This closes the Code42 app, reauthenticates the Code42 app with the Code42 server, and then restarts the Code42 service.

Step 2: Test your connection

If you're still not connected to the destination, use a command line utility to test your network connection and further diagnose the issue. Use it to see if your computer can talk to CrashPlan PRO Online.

  1. Open the Command Prompt (Windows) or Terminal (Mac/Linux):
    • Windows: All Programs > Accessories > Command Prompt
    • OS X: Finder > Applications > Utilities > Terminal
  2. Enter the appropriate command for PowerShell (Windows only), Netcat (Mac and Linux only), or Telnet.

If you're able to connect, but not the Code42 app, it's frequently due to antivirus software blocking the Code42 app. It's also possible, but less likely, that your firewall is blocking the Code42 app. Proceed to Step 3 for further details on troubleshooting antivirus and firewall software.

Test fails to connect

If a command line utility test cannot successfully connect, you may see a "connection refused" message, no response, or some other response. The most common cause that we see for this issue is that a firewall is blocking CrashPlan. Proceed to Step 3 for further details on troubleshooting firewalls.

Step 3: Check for conflicts with your firewall or antivirus software

Antivirus software

Antivirus software is designed to protect your system against unknown applications and unauthorized Internet activity. Consequently, you may need to add the Code42 app as an approved application in your antivirus or security software in order for the Code42 app to function properly. The following antivirus and security applications have been known to prevent Code42 app connections.

Applications Known To Cause Conflicts
  • Avast
  • AVG
  • Avira
  • BeyondTrust PowerBroker (version 6.5)
  • Charter Security Suite
  • CleanMyMac
  • Covenant Eyes
  • ESET
  • Intego NetBarrier
  • Intego VirusBarrier
  • Little Snitch
  • McAfee
  • One Periodic Hands Off!
  • Qustodio
CrashPlan version updates
When the Code42 app is upgraded to a later version, antivirus and security software may consider it a "new" application and block its activity. If this occurs, re-add CrashPlan as an approved application.


Your computer may have other software firewalls installed. If you are using a firewall, you may need to add CrashPlan for Small Business as an approved application, or allow outgoing access to TCP port 443.

Diagnose security software conflicts

To determine if your antivirus software or firewall is blocking access to the destination:

  1. Temporarily disable all antivirus and firewall software on your computer.
    See External resources for links to commonly used firewalls and antivirus software.
  2. Open the Code42 app.
  3. If you still do not have a connection to the destination, repeat Step 1: Manually attempt to reconnect above.
  4. If you are able to connect, individually re-enable any software you disabled (one piece of software at a time) to determine which application is blocking CrashPlan for Small Business. If CrashPlan for Small Business connects to the destination with the antivirus or firewall applications disabled, then there is a conflict between CrashPlan for Small Business and the application or firewall. Consult the application's documentation to:
    • Create an exception or rule for CrashPlan for Small Business
    • If possible, create an exception or rule to allow outgoing communication on TCP port 443
    • If possible, create an exception or rule to allow traffic addressed to * (using a wildcard in the exception allows traffic to any our servers)
  5. After adding antivirus software or firewall exceptions, open the Code42 app to check your connection status. If you are still unable to connect, repeat Step 1: Manually attempt to reconnect.

See External resources below for links to instructions for commonly used antivirus applications, as well as Windows and Mac firewalls.

Re-enable your firewall and antivirus software when you are done testing your connection.

Step 4: Verify your router allows connection

If you are still unable to connect after resolving any conflicts, a firewall on your router may be preventing the connection. However, it's worth noting that we only rarely see routers causing connection issues for CrashPlan for Small Business customers backing up to CrashPlan PRO Online.

If possible, connect your computer directly to your modem. If you are able to connect to the destination when directly connected to your modem, then your router is the source of the issue.

Still having trouble?

If the connection issue persists, please contact our Customer Champions for CrashPlan for Small Business support.

Include the results of the troubleshooting above to help our team identify the issue as quickly as possible.

External resources