install_system_update Script through Package Studio is failing
Something doesn't add up here. The failure is related to an mxconfig script and not an install_system_update script. Its almost as if you have two packages being assigned with different methods for updating the OS. install_system_update will trigger it directly with an intent pass whereas you also seem to be calling an mxconfig script somewhere on XML that was potentially StageNow generated MX. Whatever you're doing seems to be redundant.
LifeGuard updates are also better suited for File Sync rules since they can be large and clog up your MobiControl DB as packages. File Sync rules use the server storage directly, outside of the DB.
I'm not an expert but perhpas try to rename the file name.
Because I see the name contains two dot ..
try and tell us
I went back and looked at the package itself and I think I found the issue. The project I have pictured above is Version 1.1, while I still have the package set to use version 1.0. In version 1.0 I was using MX to move the file, this was before I figured out how to use File sync. SO now I am using File sync and updated the package, but never switched it to the new version. There were a few weeks in between this happening so I must have over looked it. I have reassigned it and hoping it goes well tonight.