Outlook 365 suddenly won't open

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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


168 Replies

@Steven_F_603  I am in the same boat I disabled addins, no luck, I was hoping I could uninstall the latest O365 update, but the control panel app just uninstalled O365 completely,  I am going to reinstall and see what happens.  All after last night's update.



See solution here - worked for me - rolled back to previous version - that was easy - only took 3 hrs to fix :)

Mismo problema en Chile, tengo varios clientes con diferentes servicios de office y outlook tanto OWA como aplicacion de escritorio no funcionan, la de escritorio se abre y se cierra sola.@Steven_F_603 

@Steven_F_603 I have the same problem as others.  I was able to open in "Safe Mode."  You have to manually approve loading of pictures.  At least there is access until they get it fixed.



Same here.  12:57 pm. CDST


Has there been any update to this issue? I had uninstalled Office 365 and reinstalled it , Same thing, outlook wont open even in safe mode. But yet Word opens fine with my options and all.  So to me it seems like an issue with an update with Outlook maybe?


same thing here.  It worked this am (app still open from last night).  Once I closed the app, I couldn't reopen it.  Strangely, I closed the app to restart the computer because a different app (Quickbooks) wouldn't open.  Once I restarted, quickbooks would open but outlook wouldn't.  Restarted again and outlook still wouldn't open.  On autoupdates.  Other office products - word, excel, powerpoint - all are working.

Same issue... restarted, shut down, ran CCleaner, AntiVirus, etc... no access to Outlook... help!



The exact same thing happened to me 30 minutes ago. Nothing has changed on my computer and I have never had a problem with Outlook before this.

@fdupuisI have the same experience. Outlook stopped launching or opening correctly this morning. I can open in safe mode. If I try to open it in the regular mode, it does not open (interestingly, I do see an Outlook icon in my system tray like usual, but if I click it, it just disappears!)



Same problem over here.  I cannot even get Outlook 365 to open in safe mode.  Word and Excel work perfectly.  Desperate for a solution

@Joshua Bowers   Mine has two updates that are pending.  They did not download.  I guess this is a Microsoft issue on their end?


I have same issue... in Seattle, WA   @Steven_F_603 


It opens in safe mode. I tried to trouble shoot by disabling add-ins but no luck. After reading this thread, it sounds like a MSFT issue.



This worked on Office 2016. Going to try Outlook 365


Replying to
Open cmd
Run: cd “\Program Files\Common Files\microsoft shared\ClickToRun”
then: officec2rclient.exe /update user updatetoversion=16.0.12827.20470

Looks like this is a pretty big issue. I'm running a new install and, as of today, re-install of Office 365 with the same issue. Outlook will not even start in safe mode and when I try to download the SARA tool I get: "This solution isn't supported for your Office environment." Not happy. Awaiting response with you...

@Fidofelix l have the same issue, after downloading the latest updates.

@Steven_F_603 Yes having the same problem, along with several others in my company.


Get on it Microsoft and give us a fix asap!


Same here : Try this > (Open in safe mode) Use Ctrl + Open Outlook via Icon, then open Options >> and check Prompt for a profile to be used. Then click OK. This opens in safe mode for me, although only a temporary fix.

Same issue with Outlook 2016.