Outlook 2016 for Mac crashes immediately after startup

Original KB number:   3014451


Microsoft Outlook 2016 for Mac crashes immediately after startup. The crash reporter displays the following error information.

Exception Codes: 0x0000000000000002, 0x0000000000000000Application Specific Information:

dyld: launch, loading dependent librariesDyld Error Message:
Library not loaded: @rpath/osfcore.framework/Versions/A/osfcore

Referenced from: /Applications/Microsoft Outlook.app/Contents/MacOS/Microsoft Outlook
Reason:image not found


This problem occurs if the underlying file system is formatted as case-sensitive. In this scenario, the file is named OsfCore.framework. However, Outlook 2016 for Mac looks for a file that is named osfcore.framework and cannot find the file inside the app bundle.


To work around this problem, rename the OsfCore.framework file as osfcore.framework. To do this, follow these steps:

  1. In Finder, open the Application folder.
  2. Right-click Microsoft Outlook, and then select Show Package Contents.
  3. Open the Frameworks folder, and then find the OsfCore.framework file.
  4. Select OsfCore.framework, press Return, and then change the file name to osfcore.framework.

More information

You can use Disk Utility to determine whether the file system is formatted as case-sensitive. To do this, run Disk Utility, select the hard disk drive partition, and then select the Erase tab to view the Format option that's selected. If either of the case-sensitive options are selected, you may experience this problem.