Office apps stops working when another Outlook started or running

Copper Contributor



I've just upgraded to the latest Insider build (16.0.14226.20004) 64-bit and I'm experiencing the same thing on 2 machines.  If Outlook is open and I open Word, Excel or PowerPoint, Outlook becomes non responsive, does not appear when clicked on from the task bar etc.  If these apps are open and I try to open Outlook, if fails to appear.  Both application behave badly.  Once I terminate one (right click on the icon on the task bar and click close), after a few moments, life returns to normal.  I can have Word, Excel and PowerPoint open together. It is only Outlook that makes things go bad.


I'm running on windows 10 - 21H1 - 19043.1081 and I can confirm the same issue on Insider Dev build of Windows 11.


Any help as to how to diagnose and resolve?





10 Replies
I have the identical issue on two very different machines as well.
My Surface Book 2 and my Ryzen-based desktop both experience a freeze. It's not just Outlook - It seems to be any two Office applications (e.g. Word & Excel or Outlook & Powerpoint) causing the symptoms.



Sorry to hear this is happening to the both of you. If this continues to happen, please reproduce the issue and report it through the app. Steps on how to send feedback can be found here. 




Hi @Evan 

Thanks for taking the time to reply.  The funny thing is, there is no way to use the application to submit a report because both apps freeze up almost instantly when the second application opens.  Trying to open a third application (say Outlook, then PowerPoint, then Excel) only the splash screen of the third application will appear and won't progress any further. 


I need to use Task Manager to kill all Office processes and then just use one application at a time with the current beta build. 





I am having the same issue / seeing the same situation. One application open is fine, second application and all become unresponsive.

@ShaneRBlake I rolled back from 2107 to 2106 (just changed the beta channel to preview instead) and all the office apps fly super fast now.  There's something wonky in the beta build. 


It FEELS like it is I/O bound:  CPU activity is only 15%, no disk or LAN activity and I have 32gb of memory (only using just above 8gb when the apps freeze).  Other apps are affected and slowed down or made less responsive including task manager (though, once TM is running it works the way it should).  The apps are competing for a resource it feels like.   I get the same symptoms on my much less powerful laptop.



@W-Archer I have done the same thing (reverted to Preview). All good here.

I have same problem, i thought it was windows 11 though, not office.

Same issue on my 2 computers. It is definitely build 2107 14226 because after restoring to 14117 everything works good.
Now I've temporally switched to preview 2106 14131 so I can use Office normally.

I am having the exact same problem as reported by the others.  Outlook works fine on its own as do the other office apps such as Word, but when Outlook and Word are running together, both are non-responsive and must be terminated from the Task Manager.   I'm running Version 2107 and Build 14226.20004.

It appears that Microsoft have just rolled back that build and on the Beta channel I've been reverted to 16.0.14217.20002.  I guess it really was a bad build!