Hi,
HairCluster and GuideCluster operators have been replaced with the Clump operator. If you still want to use those operators use the following MEL commands in the script editor.
For HairCluster operator: OxAddStrandOperator "" "HairClusterNode";
For GuideCluster operator: OxAddStrandOperator "" "HairClusterNode";
Jeordanis Figuereo (Product Designer. EPHERE Inc.)