Symantec AntiVirus Error: "Microdefs Error" while downloading updates through LiveUpdate

Article:TECH103744  |  Created: 2008-01-16  |  Updated: 2012-03-05  |  Article URL
Article Type
Technical Solution



Symantec Endpoint Protection (SEP) or Symantec AntiVirus Corporate Edition (SAV) for Macintosh is installed on a Macintosh OS X computer. When LiveUpdate is run and the progress bar is almost to the end, the update stops and a "Microdefs error" is produced. Virus definitions do not update.



  • No obvious errors in the LiveUpdate log (/Library/Application Support/Symantec/LiveUpdate/liveupdt.log).
  • Onscreen, the following is displayed:
    Microdef error
    LiveUpdate had an error updating the virus definitions.



  1. Symantec Endpoint Protection  for Macintosh 11.0.6x on any supported Macintosh OS X operating system.
  2. Symantec AntiVirus Corporate Edition for Macintosh 10.1.1 on Macintosh OS X version 10.5 (Leopard)



For Environment Scenario #1, it is possible that file permissions within the Antivirus Engine folder are incorrect.

For Environment Scenario #2, LiveUpdate 3.5, included in the install for Symantec AntiVirus 10.0 for Macintosh, is not compatible with Mac OS X 10.5.x (Leopard). Running LiveUpdate 3.5 will update the Symantec AntiVirus application to 10.1.1, but it will not update the LiveUpdate application itself beyond 3.5.


For Environment Scenario #1, if applying the Intelligent Updater does not succeed:

  • While in Terminal, type cd /Library/Application Support/Symantec/AntiVirus/Engine
  • Enter the following command to list details about the folder: ls -al
  • Look for the following files and verify whether the permissions are correct, as shown below:
    -rw-r--r--   1 root  admin    337744 Feb 23 17:33 navenmac.dlb
    -rw-r--r--   1 root  admin   3379384 Feb 23 17:33 navexmac.dlb
  • If the permissions read -r--r--r-- they are incorrect. To correct them use the following command: chmod 644 *.dlb

If any other engine folders exist (for example Engine20101004) examine the permissions of those .dlb files as well and correct if necessary.

For Environment Scenario #2, update to SEP for Macintosh 11.0.6 or greater, or to SAV for Macintosh 10.2 for Macintosh for full Mac OS X 10.5 (Leopard) compatibility. This release includes a version of LiveUpdate (5.x) that also compatible with Mac OS X 10.5 (Leopard).

Information on obtaining program version updates or upgrades can be found in the following Knowledge Base article:
"Obtaining an upgrade or update for Symantec AntiVirus Corporate Edition or Symantec Client Security"

Please note:

Symantec AntiVirus Corporate Edition 10.1.1 and earlier is not supported or compatible with Macintosh OS X version 10.5 (Leopard)

If the drive in question is a non-default, HFS Extended (Journaled, Case Sensitive) volume, the update process will fail. The drive will need to be reformatted as a standard HFS Extended (Journaled) drive.

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