Begin by closing Outlook in normal mode. The next step is to open the Run dialog, you can do that either by clicking on the smart menu and selecting run, or pressing the Windows and R keys to launch the Run dialog. If Outlook won’t open in Safe mode, ensure that you are following the instructions correctly or restart your system and try again. Enter Outlook.exe / safemode in the Run dialog box and press enter. Outlook should open in Safe mode now.

#outlook won’t open in safe mode

How to open Outlook in safe mode?
2.15 GEEK