Hi k, as I told you before, it's a random issue, and we can't be sure that someday Trend Micro antivirus do not make fail detection again.
LIGHTCONVERSE perform a lot of network and interprocess communications that's why we highly recommend to disable any software that can generate possible problems: Antivirus, Firewall, UAC, etc.
So, your customer have a choice: use version 41.2F or play a lottery with virus finding in a place where it absent

.