• IT@UC Knowledge Base

 Clearing Skype (Lync) for Business Cache

 Instructions for clearing the application cache in Skype for Business for both Mac and PC

Skype for Business (Skype, previously Lync) caches files locally on your computer to improve use by pulling information quickly and efficiently.

     To Clear Cache in Windows Skype for Business
     To Clear Cache in Lync 2011 for Mac OS
     To Clear Cache in Mac Skype for Business


A.   Common reasons you might want to clear the Skype for Business cache include:

1.      You can't log in to Skype.

2.      Your Outlook and Skype integration is not functioning properly.

3.      You have issues with the Presence Indicator in Skype.

4.      Your Contact list is out of date.

5.      You cannot search for users in Skype.

B.   To clear the cache in Windows Skype for Business

1.      Click the gear in top right-hand corner.

2.      Choose File – Sign Out to log out of Skype.

3.      On the Sign In window, choose the link to Delete my sign-in info.


4.      In the pop-up window to forget sign in info, click Yes.

5.      Click the gear, choose File> Exit to exit and close Skype.

6.      Open the Run bar (in Windows, click the Start button, type Run in the search bar)

7.      In the Run window type %AppData% then click OK.

8.      Verify that the window opens in the AppData directory.

9.      For Skype for Business, navigate to Local\Microsoft\Office\16.0\Lync\ 

o   NOTE: The “16.0” may vary based on your version of office (i.e. “16.0” for 2016 versions).

10.  Locate the sip_YourProfileName@ucmail.uc.edu folder and delete it.
If you do not see this folder, check the \Local\Microsoft\Communicator directory.

11.  Open the Tracing folder and delete all files in in it. Do not delete the Tracing folder itself.
NOTE:  If you receive a message that the action can't be completed because a file is Open or that you need Administrator permission to delete a file, click the Skip button. If it won’t delete some files because they are open in Outlook, close Outlook, then delete the remaining files.

12.  Open a command prompt (in the Windows Search field, type Cmd then select the command prompt from the menu)


13.  In the Command Prompt window, type ipconfig /flushdns and press the Enter key on your keyboard to run the command and clear the DNS cache. Once complete, click the X in top right corner of the Command Prompt window to close it.

14.  Click the Windows Skype for Business icon to reopen the program.

C.      To clear the cache in Lync 2011 for MAC OS

1.      Log out and quit Skype.

2.      Go to Finder 

3.      Press Command+Shift+G

4.      Enter /users/<YourMacUsername>/library then hit Return

5.      Delete the following files:

o   Caches > com.microsoft.Lync

o   Internet Plug-Ins > MeetingJoinPlugin.plugin

o   Keychains > all files beginning with OC__KeyContainer

o   Logs > Microsoft-Lync-x.log and Microsoft-Lync.log

o   Preferences > com.microsoft.Lync.plist

o   Preferences > ByHost > MicrosoftLyncRegistrationDB.xxxx.plist

6.      Go to Finder 

7.      Press Command+Shift+G

8.      Enter /users/<YourMacUsername>/documents 

9.      Navigate to Microsoft User Data

10.  Delete the following folders: 

o   /Microsoft Lync Data

o    /Microsoft Lync History

11.  Open Keychain Access from the /Applications/Utilities folder and delete all keychains starting with OC__KeyContainer.

12.  In your Login keychain, delete all e-mail address certificates.

13.  Empty Trash.

14.  Click the Windows Skype for Business/Lync icon to reopen the program.

D.     To clear the Skype for Business 2016 for Mac cache

1.      Log out and quit Skype for Business.

2.      Go to Finder > press Command+Shift+G

3.      Enter /users/<MacUsername>/library

4.      Delete the following files:

o   Containers > com.microsoft.SkypeForBusiness

o   Internet Plug-Ins > MeetingJoinPlugin.plugin

o   Logs > LwaTracing

o   Saved Application State > com.microsoft.SkypeForBusiness.savedState

o   Preferences > com.microsoft.skypeforbusiness.plugin.plist

5.      Open Keychain Access from /Applications/Utilities folder.

6.      Delete all keychains starting with Skype For Business.

o   NOTE: You may have to unlock your keychain by using your password.

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