Ignore this, After hours of messing around and getting the same error over and over. I finally fixed the issue 4 minutes after posting for help. It turns out Windows 10 was the culprit, Windows has had a new build "1903" I believe and the Windows AV that comes with it doesn't install on its own (neither did the update,for me at least) anyway, the old windows 10 build doesn't like Launchbox 9.10 and the Windows Defender was shutting it down instantly.
I have seen people posting the same error I was getting, the update fixed everything for me. I did get one issue where windows seen launchbox as ransomware and gave a red box and refused to launch. Just disable Windows defender for the first run and then turn it back on.
Mine is now working with all old and new themes and plugins, hope this helps anyone else having the same issue.