. xtabond2  cr L.cr  ocl bs pidd pisd cd size age roe ind  yr2004- yr2010,gmm（bs pidd pisd cd size age roe l.cr ）iv(ind  yr2004- yr2010) nolevel small nomata
ind dropped because of collinearity.
yr2004 dropped because of collinearity.
yr2005 dropped because of collinearity.
yr2010 dropped because of collinearity.
Building GMM instruments.
gmm（bs pidd pisd cd size age roe l.cr ）iv(ind  yr2004- yr2010) invalid.
r(198);

大家看下这个无效错在哪？stata的r帮助解释太简单了……