:BIRTHDAY: without any date is an invalid date for the sexp.

org-contacts-anniversaries loops through all valid contacts (headlines with
an :EMAIL: property) for any that contain the :BIRTHDAY: property (by
default, this can be customized).

When there is no date associated the value is nil.

(calendar-gregorian-from-absolute
  (org-time-string-to-absolute anniv))

Where anniv is the date retrieved from :BIRTHDAY:. nil is not a valid date,
so the expression fails, giving you a bad sexp.

On Tue, Nov 8, 2011 at 6:25 PM, Marius Hofert <marius.hofert@math.ethz.ch>wrote:

> >>> (load-library "diary")
> >>>
> >>> This calls the function load-library with the string argument "diary".
> >>> This form can be added to .emacs. Alternatively, you can use the
> >>> require form that I posted:
> >>>
> >>> (require 'diary)
> >>
> >> I obtain (also for (load-library "diary") ):
> >> File error: Cannot open load file, diary
> >>
> >> I assume I'm missing some diary.el (?).
> >>
> >
> > Nope, I'm wrong: diary-anniversary is in diary-lib, so the
> > correct form is
> >
> > (load-library "diary-lib")
> >
> > or
> >
> > (require 'diary-lib)
>
>
> okay, that's also what I tried and it worked. However, I still see the
> "Bad sexp..." error when there is a BIRTHDAY tag *without* date, so just a
> line containing ":BIRTHDAY:" But that's of course not a big issue.
>
>
>