st: numlabel gives syntax error on one specific dataset

[Graham Wright <gwwri@brandeis.edu>]

So I've often used the command

numlabel, add force

to make sure I can see the numeric values of the labels of the variable 
I'm working with and it usually works fine, but on this one dataset the 
command doesn't work.  I get the following error message when I try

nothing found where subexp expected
r(3000);

and r(3000) says that it's a Mata syntax error message, but I'm not 
using mata!

I even get the error when I generate the complete syntax using the pull 
down menu:

. numlabel, add mask("#. ")
nothing found where subexp expected

But this is only on one specific dataset, On every other dataset I open 
the command works fine, so obviously it's not a syntax error, despite 
what the error message says. I can't think of anything weird about this 
specific dataset that would cause this command to give me a syntax error 
there and work everywhere else, but I don't even know where to look.

Anyone have any advice? I'm running version 11 and just updated today, 
but that didn't fix the problem.

-Graham Wright
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/