What does a "_OBJC_CLASS_$_CATransaction, referenced from:" compile-time error mean?

Question

Can anyone please tell me what is this error, I am trying to compile on xcode

"_OBJC_CLASS_$_CATransaction", referenced from:

  objc-class-ref-to-CATransaction in RefreshTableViewHeader.o

And this error

"_kCATransactionDisableActions", referenced from:

  _kCATransactionDisableActions$non_lazy_ptr

in RefreshTableViewHeader.o

 (maybe you meant: _kCATransactionDisableActions$non_lazy_ptr)

ld: symbol(s) not found

collect2: ld returned 1 exit status

Google was of no help.

Am I missing any framework...?

Answer 1

It is a linker error indicating that you're missing some symbols. Try to add QuartzCore framework to link with your project.