When I add a meeting to my calendar, it's stays less than one minute and disappears. When I put my boss as attendee, the meeting stays on his calendar, but disappears from mine. We're using Microsoft CRM, if that helps.
Actually, yes it does help to know you are using CRM. Meetings can disappear when you use the same email address for an Internal user and a CRM record, such as for an Account, Lead, or Contact. Remove the duplicate address to fix.
A more complete explanation for this is at Outlook Appointments Disappearing
If you aren't using CRM:
- Do you sync with a portable device?
- Have Outlook open on two computers and use Outlook 2010 or older?
- If you switch to a List view can you see the missing meetings?
- Are the missing meetings in the Deleted Items folder?
Either of the first two could mean the event is getting moved to a different calendar. This will happen if you open your mailbox on a second computer and set the delivery location to a PST file (not possible in Outlook 2013/2016). In this case though, your email will disappear from the server too.
If you can see the missing meetings in list view, it means the Day / Week / Month view is corrupt. Try resetting the view where it disappears but you may need to restart Outlook using /cleanviews switch to fix.
To switch to a list view in Outlook 2010, switch to the View ribbon, expand the Change View button, choose List. In Outlook 2007, choose the By Category view. Reset the view using the Reset button on View ribbon or by right clicking on the row of field names and choosing Reset.