What are the common problems with CrashPlan?

Tags security


This article details how to troubleshoot problems with CrashPlan. The majority of our users are able to use CrashPlan without reporting any issues. However, when issues arise, we're here to help. This article describes the most-frequently reported issues and provides solutions and next steps for each. 


Supported operating Systems

There have been some instances where Crashplan no longer offers support for "older" operating systems. 

With few exceptions, CrashPlan endpoint software supports operating systems through the end of an operating system vendor’s extended support date.

Please ensure that you are updating your operating systems to remain on supported versions.

Recently supported

  • macOS 13 Ventura 
  • Windows 10 22H2
  • Windows 11 22H2

Planned support

There are no new operating system versions CrashPlan is tracking for support during the next quarter.

Upcoming end of support 

These operating systems are approaching end of support on endpoint devices running the CrashPlan agent:

  • Windows 10 21H1: End of support December 13, 2022
  • Windows 8.1: End of support January 13, 2023
  • Ubuntu 18.04: End of support April 2023
  • Windows 10 20H2: End of support May 9, 2023

Recently unsupported

These operating systems are no longer supported on endpoint devices running the CrashPlan agent:

  • macOS 10.15 Catalina: End of support Q4 2022



Network Issues/Destination Unavailable

If an external drive destination is unavailable, the Code42 app displays the message "Archive missing - Backup location is not accessible." This error typically appears because the drive name or letter may have changed. See the common cause and solution below for your operating system.


By default, Windows does not assign a static drive letter to external drives. For instance, if a drive named D:\ is ejected from the device and then reconnected, it may be assigned a different drive letter. If the drive letter changes, the Code42 app won't recognize the drive because it's still looking for the old drive letter.

To determine if the drive letter changed:

  1. Open the Code42 app.
  2. Navigate to device preferences:
  • Code42 app version 6.8.3 and later: Select settings button Settings.
  • Code42 app version 6.8.2 and earlier: 
    1. Click Details.
    2. Select the arrow next to your device name.
    3. Choose Device preferences.
      device preferences
  1. Click Destinations.
  2. From the list of existing destinations, select the local destination.
  3. Note the letter that the Code42 app expects for your external drive.
  4. Open a file browser.
  5. Click Computers in the left panel.
  6. Compare the letter currently assigned to your drive with the letter the Code42 app has associated with the drive.

If the letters are different, assign the drive a static drive letter using the original drive letter to correct the issue.


If an external drive stops backing up on a Mac, it is likely because the drive didn't unmount cleanly (for example, after a power outage, or disconnection without ejection). When this happens, the drive can leave behind a "ghost" folder in /Volumes, even though the drive is no longer mounted. When the external drive re-mounts to your device, the "ghost" folder name is already taken, so your device adds a “1” to the external drive's name. However, the Code42 app looks for a folder with the original name, and that folder belongs to a drive that appears to be no longer connected. Use our troubleshooting guide to diagnose and correct this issue.

Backup schedule

The "Backup Scheduled - Backup scheduled to begin at X" message displays when the Code42 app is set to run between certain hours and it is outside that time period. To adjust the times that the Code42 app is able to run:

  1. Open the Code42 app.
  2. Navigate to backup set settings:
  • Code42 app version 6.8.3 and later:
    1. Select Settings gear icon.
    2. Select Backup Sets.
  • Code42 app version 6.8.2 and earlier:
    1. Select Details.
    2. Select the action menu.
  1. Next to Backup Schedule, select Change.
  2. Adjust your backup schedule as needed.
These steps assume you have permission to change your backup schedule. Your administrator may prevent editing of this setting.

Under maintenance

If you see the message, "Routine maintenance - Backup will resume automatically when maintenance completes", the destination is currently performing archive maintenance. Archive maintenance is a normal part of the Code42 app's operation. Backup will resume and the message will disappear once the maintenance process completes.

Not recognized

The "Not recognized - The destination does not recognize this device" message appears when a destination cannot successfully communicate with the Code42 app.

To reauthorize with your destination:

  1. Open the Code42 app.
  2. If necessary, sign in.
  3. Open Code42 Commands by entering the keyboard shortcut for your operating system:
    • Windows: Enter Ctrl+shift+C
    • Mac: Enter Option+Command+C
  4. Enter this command: deauthorize
    You are signed out of the Code42 app.
  5. Sign in again to the Code42 app.

Contact your administrator if you are still unable to back up to the destination after reauthorizing.

Deauthorizing from the Code42 console
Administrators can also deauthorize devices from the Code42 console. The user must still sign in to the Code42 app to reauthorize.

Alternative solution

If the solutions described above do not resolve the issue, complete the steps below to remove and re-attach your local destination without deleting the archive. 

  1. Unmount the local destination drive.
  2. In the Code42 app, remove the local destination.
  3. Mount the local destination drive.
  4. Attach the local archive.
  5. View the Home screen to check the status of your backup to the local destination.   

Backup Never Reaches 100% - Unable To Back Up Files (Windows)



When the Code42 app is unable to back up a file, the History window displays the message "unable to back up n files." This most commonly occurs when the Code42 app is trying to back up a file that is open, encrypted, or lacking proper permissions. This article addresses how to identify which files are not backing up and how to resolve the issue.


The Code42 app on Windows


When the Code42 app is unable to back up a file, the History window displays the message "Unable to backup n files" (where n is the number of files the Code42 app is unable to back up).


Identify problem files

Follow these steps to identify the specific files that are not backing up:

  1. Open a file browser and paste the following location into the address bar:
    • Installed for everyone: C:\ProgramData\CrashPlan\log
    • Installed per user: C:\Users\<username>\AppData\<Local or Roaming>\CrashPlan\log
  2. Open the backup_files.log.0 file in a text editor. (For Code42 app version 7.0, open the backup_files.log file.) 
    Most problem files can be found towards the end of the log file.
  3. A file failing to back up is noted with a "W" at the start of the line:
    W 01/06/13 12:00PM 42  - C:\Users\John\Blackberry\Backup\BlackBerry Tour 9630-1.ipd

    A file backing up successfully is noted with an "I" at the start of the line:
    I 01/06/13 12:00PM 42 50cd0afdb853e65f1f47c31407ce9a4a 0 C:\Users\Jill\Documents\Outlook Files\outlook.pst (200483653) [1,0,200483653,0,0,0,0]

Recommended solutions

Once you've identified the problem files, review the information below to determine if the files fit into one of these categories. Additional troubleshooting information is provided for each category.

May be unable to back up
Unable to back up

System files

The Code42 app is designed to back up user files (documents, photos, etc.). It is not designed to back up your operating system or applications. For additional information, see our guide about choosing what to back up.

Application files

By default, the Code42 app backs up your user folder, which contains the AppData folder for your computer. Certain files inside AppData can fail to back up with the Code42 app because they:

  • Are open and locked by the application that created them.
  • Were not created with the correct permissions for the Code42 app to back them up.

If the files that are failing to back up are located in the AppData folder, review our guidelines for backing up the AppData folder.

Open files and databases

While the Code42 app backs up open files by default, it does not have application-specific "hooks" to back up files that are always being written to (SQL databases, virtual machines, Act! databases, Outlook PST files, Exchange databases). To back up these files:

  1. Close the identified files and the applications using those files.
  2. Open the Code42 app.
  3. (Code42 app version 6.8.2 and earlier only) From Home, select Details.
  4. Select Run backup now to retry backing up the file.
Backing up open files and databases
To increase the likelihood that the Code42 app can consistently back up and recover large open files (Exchange, Outlook, SQL databases, etc.), use application-specific tools to dump/export a snapshot of the internal state to a file. See Back up open files and databases for additional details.

System permissions

In the default Windows installation (installing the Code42 app for everyone on the device), the Code42 app relies on the system user's read/write permissions to access your files. However, there are some files or folders the system user may not have permission to access. If you need to back up these files or folders, follow our tutorial to add the system user to the permissions list.

Windows Encrypting File System

You can tell whether or not a file is encrypted with EFS by the green label in a file browser.

Encrypted Folders

In order to back up files encrypted with EFS, you must install the Code42 app per user. Alternatively, you can remove file encryption using the steps below:

  1. Right-click the encrypted file.
  2. Select Properties.
  3. From the General tab, select Advanced.
  4. Deselect the option to Encrypt contents to secure data.


In Windows 8.1, Microsoft introduced smart files to conserve local hard drive space. If you include your OneDrive folder in your backup selection, you may need to make your files available offline before they can be backed up.

VSS snapshots

When the Code42 app tries to access open files, the Windows Volume Shadow Service (VSS) pauses the application writing to the file and creates a snapshot of it. Sometimes these snapshots don’t get deleted after use. Since VSS limits the permissions on those snapshots, the Code42 app can't back them up. See Understand and troubleshoot backing up open files with Windows VSS for additional details.

Here is an example VSS snapshot:


To clear VSS snapshots out of your system, do the following:

  1. Go to the Windows Start menu
  2. Search for cmd
  3. Right-click on cmd.exe and select Run as Administrator
  4. In the command prompt, enter this command:
    vssadmin delete shadows /all
  5. Press Enter


Backup Never Reaches 100% - Unable To Back Up Files (Mac)


Never reaching 100% backed up is a key indicator that the Code42 app cannot back up one or more files. This troubleshooting article describes how to identify files included in your file selection that cannot be backed up on a Mac.

This article focuses on problems with individual system files not backing up. If your personal files are not backing up, it may be due to Apple privacy restrictions introduced in macOS Catalina 10.15 and macOS Mojave 10.14. See macOS not backing up files with personal data for more details.


Code42 app running on a Mac

Under the hood

Typically, when files fail to back up on a Mac, it's due to the type of files selected for back up. Many of the files that cannot back up are located in the following folders:

  • /Library
  • /System
  • /Applications
  • /Users/<User>/Library

Files located in these folders contain system files that your device needs to operate. The Code42 app is designed to back up and restore personal files, not system and application files. If your backup file selection includes these locations, it could interfere with the priority your crucial files are backed up.

For example, files found in your Library folder are mostly temporary or cache files. The Code42 app prioritizes the most recently changed files first. This causes the Code42 app to spend too much time trying to keep up with constantly changing cache files (like your web browser cache). This can hinder the progress of more important files you truly want backed up.


You can use either of the methods below to identify which files are failing to back up.

Determine what's not backing up (basic)

  1. Open the Finder.
  2. Press Command+Shift+G, and paste the following file path into the dialog:
    • Installed for everyone: /Library/Logs/CrashPlan
    • Installed per user: ~/Library/Logs/CrashPlan
  3. Press Enter.
  4. Open the backup_files.log.0 file with TextEdit. (For Code42 app version 7.0, open the backup_files.log file.)

This document lists every file that the Code42 app has backed up. However, any log lines beginning with a "W" signify a file the Code42 app wasn't able to back up at that time.

Determine what's not backing up (advanced)

  1. Open Terminal.
  2. Enter the following command. This command lists any file that failed to back up with the Code42 app:
    • Installed for everyone: grep "^W" /Library/Logs/CrashPlan/backup_files.log.0 | less
    • Installed per user: grep "^W" ~/Library/Logs/CrashPlan/backup_files.log.0 | less 

For Code42 app version 7.0, use backup_files.log for the file name.

Recommended solution

Modify the file selection to include only personal files.

General Authentication Issues/Cannot connect to background service


The vast majority of authentication issues are solved by ensuring you're logging on with the correct username (NetID@uic.edu) and/or performing a complete uninstall/re-install of the application. 


Please see the following Link for instructions on completely uninstalling and re-installing the application.


Article ID: 1558
Tue 1/19/21 9:58 PM
Wed 7/12/23 12:35 PM

Related Services / Offerings (2)

CrashPlan is an online backup service that boasts an excellent interface, unlimited storage plans, and the ability to back up to your own internet-connected computers. CrashPlan is not offered for server backups, or personal data from privately-owned computers, but is available for backups of UIC-related data on individual UIC-owned devices.
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