itunes 9.1.12 can't sync apps, but can sync other others

[kl281071]

Hi, my ipad won't synch apps, but it can sync music or ebooks. i get an error "attempting to copy to ipad failed. An unknown error (-23). Followed by another error msg "...because a connection cannot be established to the ipad"

 

[MikesTooLz]

Are these apps you paid for in the itunes app store?