I had the same problem as the toggle button to turn on and off new outlook disappeared. Luckily I found the url/pst below. I did this and it magically reappeared! My New Outlook on/off button is back!
https://answers.microsoft.com/en-us...h/68aa2e5e-5de7-4ca7-b2e8-9b48fb92bca7?page=2
From the URL above:
I also had the problem that Outlook could not be switched to the new mode. I solved this by manually adjusting the settings with the terminal:
Attention: the settings are case-sensitive!
1.) First, let's see if there is a corresponding value:
defaults read com.microsoft.Outlook EnableNewOutlook
Result:
2021-03-23 12:17:53.102 defaults[45426:841968]
The domain/default pair of (/Users/Username/Library/Containers/com.microsoft.Outlook/Data/Library/Preferences/com.microsoft.Outlook, EnableNewOutlook) does not exist
2.) Writing the settings:
defaults write com.microsoft.Outlook EnableNewOutlook -integer 3
3.) Checking the settings:
defaults read com.microsoft.Outlook EnableNewOutlook
Result:
3
Possible options:
0 = Switch hidden (default)
1 = Switch displayed, default off
2 = Switch displayed, default on
3 = New Outlook enabled with switch hidden
With "defaults read" and "defaults write" values in the corresponding settings files (PList) are adjusted. Please use this way only if you know what you are doing ...