The connection to Microsoft Exchange is unavailable when adding meeting into calendar

What:

Windows 7 with Microsoft Office 2007 in cache mode

Problem:

While trying to save a new meeting in calendar, Outlook shows a following message.

After clicking OK it's being saved.

Solution:

1. Navigate to: Start > Control Panel > Administrative Tools > Windows Firewall > Advanced Setting
2. Click Inbound Rules and select “Microsoft Office Outlook”
3. Click “Protocol and Ports” tab
4. Change protocol type from “UDP” to “Any” then click “OK” button to exit and saved to change.
5. Navigate to: Start > Control Panel > “Mail (32bit) icon > “E-Mail Accounts”
6. Click Change > “More Setting” > “Security” tab
7. Un-tick “Encrypt data between Microsoft Office Outlook and Microsoft Exchange” then click “OK” to save the changes and exit