Many people worldwide are experiencing crashes with Outlook, immediately after opening it. It's tempting to blame Microsoft Patch Tuesday (which was yesterday) but some of my clients are seeing it with not yet having the 2020-07 updates installed.

Instead, it appears to be a bad Office update. It's possible to roll back to the June 24 version of Office, which is apparently not affected by this issue: https://www.reddit.com/r/sysadmin/comments/hrq0mn/outlook_immediately_crashing_on_open_after/fy5nnx2/

Outlook is working fine for me so I haven't tested this to see if it works. If it does work for anyone affected it'd be nice to get some feedback.

If you don't want to roll back Office, my clients are finding that starting Outlook in Safe mode allows it to work: Run...outlook.exe /safe . However, in this mode any add-ins you have installed won't work.

On a very small sample size, it looks like users who have 3rd-party add-ins installed in Outlook are affected (e.g. Adobe Acrobat DC, Nitro PDF) but those who have no 3rd-party add-ins are not affected. But again, this is based on a very small sample size.

UPDATE: Microsoft has apparently published a fix. Assuming that works, most users should not need to take any action and may not see this issue any further.

https://support.microsoft.com/en-us/office/active-investigation-into-outlook-crashing-on-launch-9c59ad4b-813c-432a-afdc-f14717a4528d?ui=en-us&rs=en-us&ad=us