The SHN Utility does not come with the SmartLabs SDM3 Device Manager. That would normally come from the Smartlabs web site but that software is so old I’m not sure they provide it anymore. HCA must have the SDM3 Device Manager files in their directory structure rather than having done a normal SDM3 install which would allow all applications access to it.
Search through the HCA directory structure. Some products keep the SDM3 files in a Smartlabs or Smarthome subdirectory. The *.ump files along with the SDM3 exe should be there or perhaps in an HCA subdirectory.
I thought it easier to locate the SDM3 files in the HCA directories rather than trying to locate the SDM3 install package somewhere.