A spate of recent updates caused problems in Outlook and the short-term fix is to uninstall the update; however, updates can’t be uninstalled from the Click-To-Run installations of Office, and almost all users have the Click-To-Run installation.
Instead, you will need to revert to an earlier version.
First, you need to disable Office updates. If you don’t disable updates, the problem update will reinstall itself. You can disable updates from the File menu in any Office application.
In Outlook (this is an Outlook help site after all), go to File, Office Account, Update Options and click on Disable Updates.
Next, create an appointment in your calendar for 30 days from now to remind yourself to check for updates. In many cases, the “bad” file will be removed or replaced with a corrected update, and you can allow Office to install updates without reinstalling "trouble" after a few weeks have passed.
Now you’re ready to roll back the click-to-run installation.
Right click on the Start button and choose Command Prompt (Admin). If you don't see Command Prompt on the menu, you'll need to type cmd on the Start screen to find the Command Prompt then right click on it and choose Run as Administrator
If you are using Outlook 2016, copy the following line, then right click in the command prompt window to paste it. Replace xxxx.yyyy with the build number you want to revert to. You can look up build numbers at Version numbers of update branches for Office 365 clients.
"C:\Program Files\Common Files\microsoft shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.xxxx.yyyy
This is the March 30 2021 build.
"C:\Program Files\Common Files\microsoft shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.13901.20312
Outlook 2013 users will change the directory to the path of officec2rclient.exe. To do this, in the command prompt window, type (or copy and right-click paste) the following if you are running 64-bit Office:
cd %programfiles%\Microsoft Office 15\ClientX64\
or this if using the 32-bit version of Office:
cd %programfiles%\Microsoft Office 15\ClientX86\
You’ll revert to a previous version of Office by running officec2rclient using a command line in this format, where 15.0.xxxx.xxxx is the previous version.
officec2rclient.exe /update user updatetoversion=15.0.xxxx.yyyy
The command line you'll use will look something like this (this is the July 2014 build):
officec2rclient.exe /update user updatetoversion=15.0.4631.1002
You can get the Office 2013 version numbers from Microsoft Office 2013 Click-to-Run virtualization or Office 2016 versions here: Version and build numbers of update channel releases for Office 365 clients
Choose Online Repair. Once repair is complete you can check your version to verify it updated properly. Note: you'll probably be asked to log in again and verify your license.
For a complete list of version numbers, see Microsoft Office 2013 Click-to-Run virtualization
How to revert to an earlier version of Office 2013 or Office 2016 Click-to-Run (MSKB)
Version and build numbers of update channel releases for Office 365 clients