st: Mata run time error r(3499)

[Ebru Öztürk <ebru_0512@hotmail.com>]

Dear All
 
I use tobit regression but when I command with vce(robust) I come accross with mata run-time error r(3499). The explanation of this error is;
 
3499 not found the specified variable or function could not be found. In the case of a function, it was not already loaded, it is not in the libraries, and there is no .mo file with its name.

I use stata 10 and the command for instance is like;
tobit radical collab busingrp logsales processinn, ul vce(robust)
 
I appreciate if someone can tell me the reason of this problem.
 
Regards
Ebru
  		 	   		  
*
*   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/