Warning in Waldtest.Rm(estimates.rsm) :
  
The following items were excluded due to inappropriate response patterns within subgroups: 
Warning messages:
1: In sqrt(diag(solve(parest$hessian))) : NaNs produced
2: In sqrt(diag(lres$W %*% solve(parest$hessian) %*% t(lres$W))) :
  NaNs produced
