I tunes want to delete my ipad applications

Hello,
recently and all of a sudden i tunes start to give a message when i sync applications
that all my applications will be erased if i continue sync and start to remove them.

i changed instalous setting to not sync with i tunes but problem persist.
i removed i tunes and install old version which was working before but problem persist.
i tried transfer purchases but transfer failed as the computer in niot authorized i deauthorize and reauthorize it but transfer purchases failed.
at this point i stopped .
what can i do .