Outlook won't start

New Contributor

"Cannot start outlook. Cannot open the outlook window. The set of folders cannot be opened.  An unexpected error has occurred"


I followed all the steps so far in the help section.  Will open on the 3rd attempt if you click yes to "do you need help"..  then cannot open a help ticket.. 




Help please?


4 Replies
Downloaded from Office 365 on PC Windows 10..
best response confirmed by Martin_Hughes (New Contributor)
IMHO, those errors point to a corrupt PST. Try turning off cache mode, or delete your mail profile and create a new one

@mmorganMIT IMHO you are a bleedin' legend! Profile it was. New profile fixed it.  Thanks so very much!

Hi Martin_Hughes,


Outlook may fail to open due to various reasons such as problematic add-ins or extensions, corrupted files, or issues with the navigation pane.

Try some workarounds that will help you

1. Install updates for both Outlook and Windows operating systems.
2. Deactivate any add-ins that may be causing the problem.
3. Restore your Outlook profile to its default settings.
4. Fix any corrupted Outlook data files.
5. Verify the settings for your Outlook mail server.

If you don't know how to carry out these actions, please inform me, and I'll provide you with step-by-step instructions.