Outlook On The Web Error when Saving Calendar Appearance / Reminders Options

I have been meaning to post this for a while now and well life and work sometimes get in the way of sharing the nuggets of info from my job.
So here is the scenario we were running into:
upon migrating an Exchange 2013 Mailbox to Exchange 2016 CU1 some users when adjusting their calendar appearance or setting the option to send a daily agenda email would get an error when saving their settings. The user would get an error that "There was a problem saving your changes. Please try again." you would then see a correlating error in the event viewer with Event ID: 4999 on the server the user was connected to. After working for several days with support, we found that within the mailbox calendar configuration the weather location bookmark was set to a -1 rather than a 0. This setting is currently only used in the O365 and we are not sure as why when migrating a user this bit gets flipped for some users.
you can see this property value by running a Get-MailboxCalendarConfiguration -Identity |FT ID*,Weather* we found that the only way to reset that value was to use MFC Mapi and delete the IPM.Configuration.OWA.useroptions from the users mailbox.

To find all Mailboxes affected you can run:
Get-Mailbox -Server <ServerName> -ResultSize unlimited | Get-MailboxCalendarConfiguration | Where {$_.WeatherLocationBookmark -ne "0"}| FL Id*,WeatherLocationBookmark

to Resolve:
1. Download the latest version of MFC Mapi
2. Grant yourself Full access to the effected users mailbox (Add-mailboxPermission -Identity -User -AccessRights FullAccess)
3. Ensure the user has MAPI access enabled
4. Open MFC Mapi

a. Click Session > Logon

b. Locate the mailbox on the right hand side and double-click it

c. Right-Click the Root Container and chose Open Associated Contents Table

d. In the new window that opened scroll to the right till you see the Message Class Column

e. Scroll down till you locate the IPM.Configuration.OWA.UserOptions Message

f. Right-Click IPM.Configuration.OWA.useroptions and chose Delete Message

g. In the Delete Item Window click OK

h. Close all MFC windows
5. Verify issue is resolved by running Get-MailboxCalendarConfiguration -Identity <username>  | FT WeatherLocationBookmark