Outlook 365 suddenly won't open

[Steven_F_603]

Hello; Outlook worked this morning, now it won't open, says to open in Safe Mode, but that doesn't work, tries to open for 5 seconds than nothing. Restarted PC and no help. Please advise! Steven F 603

[#2]

@Steven_F_603 

Same problem here - Surface Notebook. 

Just installed the latest kb456483. kb4565633 and KB4565554.

I am in the process of removing them.

[#3]

I've had the same problem ever since I ran the latest Microsoft update this evening.  Outlook opens for a few seconds then closes so I can't access my emails!  Very frustrating!

[#4]

@Steven_F_603Ran the 2 line cmd prompt edit suggested above. Didn't appear anything was happening, but when I closed the cmd prompt the Outlook box reappeared I clicked no, don't start in safe mode a couple times. Outlook began to open (successfully) and I have a Microsoft pop-up 'Downloading Office updates... You can keep using Office while we download in the background.' Crossing my fingers. Good luck to all.

[#5]

@DebarahWilson  You can try the version rollback as suggested in this thread or as in the "Update" note on the blog article I referenced there is a fix being pushed out and you may just have to close and re-open Outlook. 

[#6]

I don't know about the OP's case but rolling back didn't help my Outlook situation at all.

[#7]

Outlook just came up ok, I am in UK, must be fixed.

[#8]

So awesome!  I just rebooted and opened Outlook 365 on my computer and Hallelujah, it works!  Yeah!  Thanks Microsoft for listening to all of us :)   @joncool85 

[#9]

Microsoft must have pushed out a fix, because I had not done anything since all my frustration of trying to remove add-ins and repair office.

[#10]

@Steven_F_603 

This is so frustrating.  I uninstalled the recent update and Outlook still doesn't work.

[#11]

Hi all, here's my update for you all. So I've just been through and installed the three available updates to me which includes one that was suggested uninstalled. The update took sometime, one of the updates was a full Windows update, reckon about 40 ish minutes beginning to end of install and after restarting to complete the update Outlook worked without intervention. So MS have either fixed these updates now or there's a further issue if using Outlook to synch with an online mail system running Exchange. All my email accounts are POP or IMAP so am local running Outlook only.

I'm now showing no updates available in Updates and in the installed updates the list has completely changed, I'm guessing because of the update to Windows itself. Have screen grabbed and attached my Windows version.

[#12]

@dpgarcia 

Microsoft is pushing out a fix.  It is applied simply by closing and reopening Outlook.  It may take a few more hours to reach all machines but I have seen it repair several already, as well as others have reported the same.

[#13]

Same problem here . It will open in "safe mode" but not in normal.

@Steven_F_603 

[#14]

@Steven_F_603

Same here (Germany)

Since updating Windows, Outlook doesn't start anymore. (Office 2019)

1. Trying the safe mode didn't help. Splashscreen appears, but seconds later Outlook closes
2. To downgrade to previous build from 2016 also didn't help,- same issue
3. Deleting the *.ost entry from the registry also didn't help
4. Installing the Office Suite completely fresh - no success
5. Deleting the Windows update - no success...

We cannot work with Outlook - and this is very important.

Microsoft,- it is urgent! Deliver a hotfix immediately!

[#15]

@Frank_Petrus 

This worked for me as well!   Thank you!

open cmd, run:

cd \Program Files\Common Files\microsoft shared\ClickToRun

then enter:

officec2rclient.exe /update user updatetoversion=16.0.6366.2062

[#16]

Exact same thing happened to me.   Office 365 programs all vanished as did Skype.  I had to download and reinstall all software.   @Steven_F_603 

[#17]

@Steven_F_603Same here.  And of course, I immediately deleted Bitdefender Internet Security, a couple of large PST files, anything else I could imagine might be causing the problem, then - a stroke of genius - searched for "my outlook365 just stopped working" and HERE I AM!  There was some sort of update early this afternoon, that I received notice of but never told to reboot, etc., like a normal update.  Moments like these result in the realization that we are all a few bytes away from complete bedlam.

[#18]

@JeffP357   And, just like that, back to normal; I _guess(?) I should be grateful to Microsoft for "pushing out a fix" but I would be even more grateful if they didn't do this sort of thing _ever_?  I am a little worried about Bitdefender hunting me down, based on my heated "deleting your software debrief" survey.  Oh well . . . .

[#19]

Same for me - managed to get a vital email sent via Safe Mode - tried System Restore to point before the updates from last night - and that FAILED after spinning my wheels for way too long!!!! This is totally unacceptable - my Real Estate business is majorly impacted from this forced update - I need full control over when/how/if I choose to apply operating system changes from Microsoft!!!!! I need this fixed yesterday! Who do I send the bill for lost hours!!!!!????

[#20]

Uninstall the last update! Worked for me.

[#21]

@RobWill_19 

Many thanks Rob and everyone.  Apparently my machine received the fix - Outlook is now working.

Best regards to all.

Dennis