I am not able to get the solution of installing the second instance of the webMethods instance on 9.6.
Is it like the normal process, Do I need to run the installer again to create a new instance? Is multiple instances supported on the trial version (9.6 or 9.7) ?
As you are not sure about the logs location, can you try to direct the logging to command console itself using ‘-log none’ option and check what’s going there.
Once your instance is successfully created and you should be seeing the logs folder within the instance folder on file system after the starting the instance. Can you check there.