Got this error message, and tried the fix from the existing thread but still having problems . cem totpop_07 netinc_07 disvlg_n distroad_n age edu male ccp prov (#0) if sumindexnew2 ~=., t Matching Summary: ----------------- Number of strata: 1650 Number of matched strata: 0 0 1 . All 1315 668 42 Matched 0 0 0 Unmatched 1315 668 42 imbalance(): 3258 <tmp>[1,1] found where void required <istmt>: - function returned error r(3258); Any suggestions? Many thanks Lily Tsai