Downloaded the new R9 WIP and unchecked the automatic downloading option when installing it. Now that seems to have ghosted R8’s Enable Updates, which is a change I didn’t want.
I then set enable_automatic_updates in the registry for R9 to 1. It was already 1 for R8.
Edit to ask:
1: How do I re-enable updates in Rhino 8?
2: How do I avoid affecting R8 when installing or modifying R9 WIP?