Hi all,   I'm having some issues, getting an error message: WARNING: Obtaining minimum variance quadratic unbiased estimates as starting values for the covariance parameters failed.   Basically, I have five years of data collected on plant nutrient components, having 10 evaluations per given year. We considered year as a random factor and evaluation should be the considered as the repeated measure.   My code is this: PROC GLIMMIX data=grass plots=studentpanel; class name year block eval ; model nutrient= name eval namet*eval / ddfm=kr ; random block year; random eval /sub=name*year*block type=toeph residual; lsmeans Treatment eval treatment*eval /pdiff adjust = tukey lines; ods output FitStatistics=Fout CovParms=Cout; output out=resid pred=pred Student=Student; quit;     however, whenever I change the second random statement to "Random _residual_ / sub=name*year*block type=toeph;" everything runs as it should.   Is there anything I'm missing? ... View more