Error c1038a21 appears when you try to view properties of public folder system folder – Schedule + free busy or offline address book folder Microsoft have a article on how to fix it , but in there guide they recommend usage of Information Store Viewer (MDBVu32). I prefer to use PFDAVAdmin that can be downloaded from here it is much easier . Run PFDAVAdmin Press on file>connect Fill your DC settings like on screenshot bellow (don’t forget to select public folders) Read more

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. Read more