You receive a meeting and see a small note that meeting is not in your calendar

To fix the problem do the following.

Close your outlook and search your computer for FRMCACHE.DAT file.
Make sure to select hidden and system files.

Delete it.
Restart Outlook.

Outlook should rebuild FRMCACHE.DAT file.

Other option is to to run outlook.exe /cleanreminders command line switch .

To see other command line switches look at Outlook command line switches.

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