Outlook Calendar Drag/Drop not working

Hi maheshspeaks,

Microsoft is aware of these issues and is currently investigating them.
Known issues with Outlook Desktop Shared Calendar Improvements - Microsoft Support

You can consider trying a few potential workarounds:

1. Temporarily Disable 'Shared Calendar Improvements':
   Turn off this feature and restart Outlook to see if the problem persists.

   1. In Outlook(PC), click File | Account Settings | Account Settings
   2. Double click your account
   3. Click the More Settings button
   4. Click the Advanced tab
   5. Uncheck the Turn On Shared Calendar Improvements box and click OK
      
      

       

2. Remove and Re-add the Calendar:
   After disabling the 'Shared Calendar Improvements' feature, attempt to remove and then re-add the calendar.

3. Reset Outlook Folders:
   Run the command outlook.exe /resetfolders to repair default Outlook folders.