I'm using OSX 10.8 Mountain Lion and Outlook 14.2.3

Everytime I go open a sent attachment or preform a search Outllook crashes, is their a fix for this?
How do I go back to the old?
Outlook 2011 for Mac (french)
Every time I leave and come back to Outlook 2011 some of the messages "marked as read" become "marked as non read".
If I select them and do a click right to select "mark as read" nothing happens... I have to "select all" then click on "mark as non read" and select all again and click "mark as read" to get them "marked as non read" but often when I leave and come back to Outlook 2011 some of the messages "marked as read" become "marked as non read".
It's just terrificlyboring.
Thanks for your help.
I have seen in the forum various messages on the updating identity message when you start Outlook. I have seen the reply about deleting files etc. However, today I have this message for 3 hours. It says not to force out of application or shut down.
What do I do now?
when do i have to switch over to outlook.com?
When I try to use Outlook receive mail or send this message comes up: Authentication failed because Outlook doesn't support any of the available authentication methods. That floors me! Is there a workaround for this?

Thanks for any help you can provide.
I purchased Outlook but inadvertently deleted it. Is there a way I can re-download without purchasing it again? Is there a record of my purchases?
At the moment only the default mailbox displays on the left hand pane, I would like several mailboxes to show in that pane.

Is there a way so that I can view multiple 'inboxes', 'sent items' etc associated with different users on the one outlook account?

Please advise :)
When I'm creating tasks with outlook 2011 for Mac, I cannot see them in outlook tasks. I only can find them again in the Apple reminder Apllication.
Is there anything due to iCloud? can somebody help me?
thanks