iphone & ipad won't sync after migration

I used migration assitant to upgrade to my new Macbook. When I plug in my ipad or iphone it says "I-tunes could not connect to this i-phone. Could not allocate a resource." When I look into the Itunes>Preferences>Devices my all my latest sync back ups are there. Any idea what I can do? My old computer crashed after migration, so not sure if my library and backups are still there. Thanks for any help!!