Our updater activity looks suspicious to Antivirus programs. It opens a file on another machine, runs that file, downloads things from the internet, makes a file, changes the file name, etc. All of these actions can also be said of malware.  There isn't a good error written in for this. So we get messages about not being able to write to files usually because it is across the network.

The error may be “File is Locked,” an I/O error, file used by someone else, or "unable to write to file". Different antivirus will come up with different messages.

The cause of these issues is “predictive machine learning” in Trend Micro introduced in early 2017.

Users can ask Trend Micro to exclude the LPX updates directory from scanning. This works here.  Another possibility for a "standalone" install is to not use the network path for the root folder in LPX.