Bob Cober

By default, the toolkit diretory is not writable in Windows. You can right-click the directory in Windows Explorer, and grant access to your user on the Security tab.

Also - as mentioned above - On Windows use %HFS% instead of $HFS

So that path is at obj level. Go inside newcactus in the houdini node graph and select a node there. Must be at geometry node level.

Are you getting the error when syncing from Unreal to Houdini or when syncing from Houdini To Unreal?

When sending to Unreal, make sure to use the geo path and not just the obj path. The easiest way to avoid errors in the path url is to ctl-c the node in houdini and paste in the the path in Unreal Node Sync window.