Outlook crashing when sorting emails

Super Contributor

After the Version 1808 (Build 10730.20088) (Monthly channel) update our users started experiencing problem with sorting emails. Whenever they try to sort say by From or other column (usually by From), Outlook crashes and restarts. This is happening more often when a user has lots of emails in the Inbox or single folder (thousands of emails at least). Reverting back to Version 1807 (Build 10325.20118) fixes the problem. I have opened a service request today and have collected logs during remote session (still have to upload them somewhere for MS to take, too big for email). Just wanted to post it here to get maybe some more attention as i don't trust first line support to actually forward this to Outlook team..


Updating to Version 1808 (Build 10730.20102) doesn't help (it was only a security update).

11 Replies

First rule for happy admin life - leave monthly builds to other beta testes (I mean paying customers) :)


Although I'm not seeing this on my laptop that's on 10730.20088. Sorting a folder with 20000 works fine and is lightning fast, on From or any other column. Perhaps they've made some optimization to the sorting code and left few bugs in it...


Just to be on the safe side, have you tried reproducing the issue with Outlook running in safe mode?

We thought about Semi-Annual channel. But this way you don't get new useful features fast (well, at least useful in theory), so money return for pricey licenses is less. Also, now we have to deal with one or two changes (like removing Share Workbook button, introducing AutoSave, etc.) or bugs every month. With a Semi-Annual channel you would get a bunch of issues at once. Not sure what is better for admins and less irritating for users :)


Yes, forgot to mention that in Safe Mode it works ok. It is very hard for me to reproduce it on my PC (Win7) as i have only a handful of emails in my Inbox or any other folder. I also wasn't able to reproduce it at all on a fresh Win10 PC after setting up my account in Outlook. During remote session i had to click maybe 30 times on various columns before it finally crashed. But it happens consistently after first click on From for many users (both Win7 and Win10).

Well if it works OK in safe mode, it's most likely some add-in causing this. I would also suggest disabling any AV and other types of "scanning" software.

I still can't find a clear pattern, but it indeed seems to be related to AV. If i uninstall Symantec Endpoint Protection on a crashing PC, it stops crashing. If i reinstall it back, it crashes again, through it sometimes takes longer to reproduce. I have checked tens of PCs today. Same models, same SEP version, no crashes. Only some crash for some reason. Some even show that SEP add-in has been disabled because it caused a crash. Will try to also post on Symantec forums, maybe even file a case.


There is a newer version of SEP released recently. We were planning to start testing it. Maybe it will fix this issue. Although it was released before the September updates of Office Monthly channel.

I've received a link to this KB article from Symantec (September 6) It's a classic case. Symantec says to contact MS (because of CTR version) and MS tells us contact Symantec..

The classic story of who sh** my pants :)

Yeah.. Just updated one PC to the latest SEP version (14.2). Same issue. Not sure what to do next. There is a way to uninstall Outlook scanner manually via Programs and Features > Modify. But not an option to do this centrally for all the clients, that i know of.

best response confirmed by wroot (Super Contributor)

I've been advised by Symantec support to disable Outlook scanner add-in via policies. Also had to make additional setting so clients won't show an error about the disabled scanner. Now Outlook is not crashing anymore. Symantec reasoning was that this scanner is not needed as we already have main Auto-Protect module scanning everything, also the temp files when attachment is opened or saved.

I've had exactly the same issue with my personal machine while testing 1808. Likewise, disabling the Symantec Endpoint Protection add-in within Outlook immediately resolved the issue.

Why would you have any security tools scanning Outlook anyway?  Is there something that Symantec does that you cannot accomplish with EOP?

It wasn't a decision to enable it to do something along side the EOP. It was just there for many years and this scanner is always a part of client protection package, by default. Symantec server has been setup maybe 7+ years ago when we were still on some local POP3 mail, so i actually didn't remember there were additional scanners like Lotus Notes, etc. until this issue came out. Although i can see some companies still wanting to use the scanner in case EOP doesn't catch something (who said EOP is 100% fail proof?) and if they want for a malicious attachment to get caught without it being opened by a user and then caught by the AV file system scanner.