This is the sequence of events:
1. In my home directory, created a programs folder.
2. Extracted the contents of the HERODesigner.zip file (freshly downloaded) to that folder.
3. Checked to make sure I had full read/write rights to all the folders and files.
4. Double clicked on HD6.jar.
5. It starts up, but stalls on the "Loading Plugins" screen.
I installed the HERO Combat Manager and it's working fine.
I'm at a loss, please help.