Skype for Business/Lync caches files locally on a PC or MAC to pull information quickly and efficiently. Common reasons you will want to clear Lync cache include:

  • You can't log in to Lync.
  • Your Outlook and Lync integration is not functioning properly.
  • You have issues with Presence.
  • Your Contact list is out of date.
  • You cannot search for users in Lync.

Skype for Business/Lync 2010 or 2013 for Windows

Lync 2011 for MAC

Skype for Business 2016 for MAC

Skype for Business/Lync 2010 or 2013 for Windows

  1. Log out of Lync.
  2. Delete any sign-in info.
  3. Exit Lync.
  4. Open Run bar and type in %AppData%. Make sure you're in the AppData directory and navigate to \Local\Microsoft\Office\15.0\Lync\ for Skype for Business and Lync 2013, or  \Local\Microsoft\Office\12.0\Lync\  for Lync 2010. 
  5. Delete sip_profileName folder. If you do not see this folder, check the \Local\Microsoft\Communicator directory.
  6. Delete all files in Tracing folder. Do not delete the folder itself.
  7. Clear DNS cache: in Command Prompt run ipconfig /flushdns command.

Lync 2011 for MAC

  1. Log out and quit Lync.
  2. Go to Finder > press Command+Shift+G > type in /users/<MacUsername>/library > delete the following files:
    • Caches > com.microsoft.Lync
    • Internet Plug-Ins > MeetingJoinPlugin.plugin
    • Keychains > all files beginning with OC__KeyContainer
    • Logs > Microsoft-Lync-x.log and Microsoft-Lync.log
    • Preferences > com.microsoft.Lync.plist
    • Preferences > ByHost > MicrosoftLyncRegistrationDB.xxxx.plist
  3. Go to Finder > press Command+Shift+G > type in /users/<MacUsername>/documents > navigate to Microsoft User Data > delete the following folders: Microsoft Lync Data and Microsoft Lync History.
  4. Open Keychain Access from /Applications/Utilities folder.
  5. Delete all keychains starting with OC__KeyContainer.
  6. In your Login keychain, delete all e-mail address certificates.
  7. Empty Trash.

Skype for Business 2016 for MAC

  1. Log out and quit Skype for Business.
  2. Go to Finder > press Command+Shift+G > type in /users/<MacUsername>/library > delete the following files:
    • Containterscom.microsoft.SkypeForBusiness
    • Internet Plug-Ins > MeetingJoinPlugin.plugin
    • Logs > LwaTracing
    • Saved Application State > com.microsoft.SkypeForBusiness.savedState
    • Preferences > com.microsoft.skypeforbusiness.plugin.plist
  3. Open Keychain Access from /Applications/Utilities folder.
  4. Delete all keychains starting with Skype For Business.