When Outlook 2011crashes with this error message “Outlook has encountered a problem and needs to close” when you are trying import a .pst file into it, verify you have the latest Office for Mac updates installed as well as Office for Mac Service Pack 1.
The latest updates latest Office for Mac update has some fixes that address an issue with importing .pst files.
You should always import a .pst file into a new, empty Outlook 2011 Identity. This way, if there is a problem it will not affect the data in your working Identity.
After you import into the new Identity, you can export under File > Export as .olm file. This can be imported safely into your Identity.