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Who is this article for?

Code42 for Enterprise
CrashPlan for Small Business

Code42 for Enterprise, yes.

CrashPlan for Small Business, no.

This article applies to app version 4.

Note: This app version is no longer supported.

Other available versions:

Versions 6, 7, and 8Link: What version am I on?

Code42 Support

Connect to CrashPlan Central Online

Who is this article for?

Code42 for Enterprise
CrashPlan for Small Business

Code42 for Enterprise, yes.

CrashPlan for Small Business, no.

This article applies to app version 4.

Note: This app version is no longer supported.

Other available versions:

Versions 6, 7, and 8Link: What version am I on?


If you are unable to connect to CrashPlan Central or CrashPlan PRO Online, 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.


  • If you are attempting to connect to CrashPlan Central or CrashPlan PRO Online 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 destinations, CrashPlan Central and CrashPlan PRO Online (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

You can identify and solve network connectivity problems through a 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 CrashPlan app, to help them identify the problem as quickly as possible.

Step 1: Manually attempt to reconnect

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:
  4. Press Enter
    This closes the CrashPlan app, stops the CrashPlan service, and then restarts the CrashPlan service

Running the restart command

Step 2: Use telnet to test your connection

If you're still not connected to the destination, use a simple Telnet command to further diagnose the issue. Telnet allows text-based communication between computers.

  1. Open the Command Prompt (Windows) or Terminal (OS X/Linux):
    • Windows: All Programs > Accessories > Command Prompt
      If you are using Windows 7, 8, or 10, or macOS High Sierra 10.13, you must install Telnet.
    • OS X: Finder > Applications > Utilities > Terminal
  2. Enter the command:
    telnet <> 443

Telnet successfully connects

If Telnet successfully connects, it will display a message similar to this:

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

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

Telnet fails to connect

If Telnet 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 the CrashPlan app. 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 CrashPlan app as an approved application in your antivirus or security software in order for the CrashPlan app to function properly. The following antivirus and security applications have been known to prevent CrashPlan 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 CrashPlan 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.


Firewalls are designed to prevent unauthorized network activity on your computer. Many operating systems come with a built-in firewall:

Your computer may have other software firewalls installed. If you are using a firewall, you may need to add CrashPlan 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 CrashPlan 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. If CrashPlan connects to the destination with the antivirus or firewall applications disabled, then there is a conflict between CrashPlan and the application or firewall. Consult the application's documentation to:
    • Create an exception or rule for the CrashPlan app.
    • 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 CrashPlan 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. It is more frequently an issue for establishing connections between computers.

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 Code42 for Enterprise support.

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

Include the following information in your request to help our Customer Champions diagnose the issue faster:

  • Product name helps us direct your request to the team that can best assist you
  • Operating system and version(s) of relevant system(s)
  • Detailed description of the question or problem
  • Screen shots of relevant settings in the app, console, or error messages
  • Computer ID (GUID) of affected device or devices (where's my computer ID?)
  • Logs can help us diagnose your issue more efficiently (how to find and send logs)
  • Username (or email address) of affected user account
  • Version of software you are running