Your request couldn’t be completed. This may have occurred for security reasons

Problem:

This problem happend when you are using HTTP for OWA insted of HTTPS like http://OwaServer
When the user open his OWA, it seem that everything is OK, but when opening any folder or sometime messages it just display the error message "Your request couldn’t be completed. This may have occurred for security reasons".
NOTE: This problem wont happens when the users are using HTTPS

FIX:
The solution is editing the web.config file and change the requireSSL=”true” to “false” , see the steps below :

1. Find the Outlook Web App Web.config file on the Client Access server. The default location is \Program Files\Microsoft\Exchange Server\EXCHANGEVERSION\ClientAccess\Owa.
2. Make a backup copy of the file (Important!)
3. Open the original file using Notepad. (You may need to run it as Administrator)
4. Find httpCookies httpOnlyCookies=”false” requireSSL=”true” domain=”” and change the requireSSL flag to false.

Save and close the file.

For the new settings to take effect, open a Command Prompt window, and then type iisreset to restart IIS using the command iisreset /noforce