I'm trying to use the Dendrogram tool (Spatial Analyst\Multivariate) to create a dendrogram for a signature file produced using the Iso Cluster Unsupervised Classification tool. The tool runs when I unselect Use variance in distance calculations (optional), but fails with no error message when I keep this option selected. Instead I get a pop-up that background processing has encountered a serious error and is unable to continue. Has anyone else encountered this? I was able to run the Dendrogram tool fine in 10.2.1, but now with the upgrade to 10.3.1 it fails. Signature file attached.