get stuck with math symbols

I am using company-auctex at win10, and I found that each time I open emacs 
and try to put some math symbols. The emacs will get stuck and wait for several seconds.
I think this is related to the annotation company-auctex-symbols used, and if I comment 

    ;;(annotation (company-auctex-symbol-annotation arg))))

this line, the problem will be solved.