Wondering if I could get some feedback on this error message I received running cem:


. cem strengthpid (1.5 2.5) age (25.5 45.5 64.5) educ (2.5 4.5 6.5) hhinc (3.5 5.5 7.5) male, treatment(indepvote)


Matching Summary:
-----------------
Number of strata: 290
Number of matched strata: 0

             0    1    .
      All  125  860    1
  Matched    0    0    0
Unmatched  125  860    1

             imbalance():  3258  <tmp>[1,1] found where void required
                 <istmt>:     -  function returned error
r(3258);


 Return code 3258
        nonvoid found where void required
        An argument was expected to be void and it is not.


What is this referring to?   

Thanks,

Michael Jones-Correa
Cornell