运行tsset指令时出现如下结果，似乎是字符库的问题？请问如何解决？ 

.tsset
(strtoreal() in lmatabase, compiled by Stata 10.1, is too new to be run by this
version of Stata and so was ignored)
   _TS_p_delta_getnumb():  3499  strtoreal() not found
 _TS_p_delta_increment():     -  function returned error
           _TS_p_delta():     -  function returned error
                 <istmt>:     -  function returned error