Hello EWS,
Hauptwerk v8 uses newer versions of Apple's and Qt's components than earlier Hauptwerk versions, so that it can support macOS 13 better. Hence upgrading to v8 would be recommended in any case, but it might or might not be relevant to the specific problem you're having.
However, if macOS doesn't have enough RAM free for itself, its audio system (and thus also Hauptwerk) won't produce sound. Newer macOS versions tend to need more RAM than older ones, so updating macOS can cause that problem if you were using most of the RAM for Hauptwerk in the older macOS version. Also, once the problem has occurred you would probably need to reboot before macOS' audio system will work again.
Please try:
- Reboot the Mac.
- Log in and wait a minute or so to make sure that everything has had ample time to finish booting.
- Now launch Hauptwerk.
- Load St. Anne's (which doesn't use much memory).
- Using the mouse, turn on some stops and click on some keys.
Do you hear the pipes' sound?