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  • Your Contact list is out of date.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 for Windows

Lync 2011 for MAC

Skype for Business 2016 for MAC

Skype for Business/Lync for Windows

  1. Log out of Skype for Business/Lync.
  2. Delete any sign-in info (only in Skype For Business 2013/2016)
  3. Exit Skype for Business/Lync.
  4. Navigate to Users > username > AppData > Local > Microsoft > Office > x.0 (x.0 corresponds to the Skype for Business/Lync version: 16.0 = Skype for Business 2016, 15.0 = Skype for Business 2013, 14.0 = Lync 2010) > Lync
  5. Delete sip_profileName folder. 
  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 ~/Library > delete the following files:
    • ~/Library/Containterscom.microsoft.SkypeForBusiness
    • ~/Library/Application Support > Skype folder
    • ~/Library/Internet Plug-Ins > MeetingJoinPlugin.plugin
    • ~/Library/Logs > LwaTracing
  3. Open Keychain Access from /Applications/Utilities folder.
  4. Delete all keychains starting with Skype For Business.