Cluster analysis - insufficient observations

[Leafy Stone]

Hello,

I am trying to do a cluster analysis with about 410 baseline survey variables and 2000 observations. I plan to look at symptom subgroups using dendrograms.
I keep getting the error insufficient observations r(2001). I do have quite a bit of missing data.
Does anyone have any suggestions on what the issue might be?
This is the code: cluster singlelinkage v1-v410, measure(L2) name(clustertest)

Thanks,
Jennifer

[Nick Cox]

Problems with missing values are the most likely reason for this.