Occasionally, when trying to open Outlook the application will just hang on a splash screen. Starting Outlook in safe mode may help. An error message such as “Cannot start Microsoft Office Outlook. Cannot open the Outlook Window” may be displayed.

Start Outlook in safe mode

1. Close Outlook
2. On your keyboard, click the Windows key + the R key to open the Run dialog box
    + R
3. Type Outlook /safe, and choose OK
4. In the Choose Profiles dialog box, accept the default setting of "Outlook" and choose OK
5. If prompted, enter your password and choose Accept

If Outlook successfully opens, exit and try a normal open.