Hi anonymous userummers-2109 ,
What's the version of your Outlook? (File > Office Account > About Outlook). Please make sure you have upgraded your Outlook to the latest version.
Do all of other users in your working environment have the same issue?
Since you have mentioned that everything can work fine in Outlook for web and Exchange "Online mode", it seems that your issue is more related to your Outlook desktop client. As I know, differences between Exchange cache mode and Exchange "Online mode" are OST and OAB. And usually corrupted datafile may cause issues like this.
So, in order to conduct further researches on your issue, please try to rename your outlook datafile(.ost) and then restart your Outlook to see if the issue could be resloved. You could find your datafile via File > AccountSettings > AccountSettings > Datafile > choose your email account > Open file location.
Besides, corrupted Outlook profile can also lead this issue, so please try creating and using a new Outlook profile via Control Panel > Mail > Show profile and see if there is any difference.
Update:
Thanks for your reply.
This is happening when they are trying to open a re-occurring Zoom meeting in their local outlook client. This only happens on re-occurring meetings, not on single date ones.
Are there any users who can work fine when using Outlook client with re-occurring Zoom meetings except these three specific users? If yes, please try to compare the difference between their Outlook settings and see if we could find more useful information.
As I know, Outlook itself can also create recurrence meetings. In order to conduct further researches on your issue, please try to create normal recurrence meetings(not Zoom meetings) and see if the issue has any difference.
Besides, are these re-occurring Zoom meetings stored in those users' own calendars? Or in shared calendars? If they are stored in shared calendars, it is also suggested to uncheck "Download shared folders" via File > AccountSettings > AccountSettings > Double click your email account > More settings > Advanced and see if it helps.
Any update, please feel free to post back.
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