@DOS76, are you having to manually close LaunchBox for updates? I guess I'm confused because the updater should automatically close LaunchBox/Big Box before running the setup. Are you running the setup manually or using the automatic process?
I saw this issue on multiple machines for 10.3 but so far 10.4 has installed without any issue. The installer was giving an error message that LB was still running I don't know why it didn't close it on its own. I've sporadically had this issue in the past also but it seemed very randomly. The last version was the 1st time I think that I ever saw it occur on multiple machines at the same time.