After installing Java Runtime into SMARTDAC+ GM, when accessing the recorder via Windows Explorer, the Java security warning screen appears. How do I keep this message from appearing?

It depends on the PC you are using, but you may be able to prevent the message from appearing by adding the URL of the recorder to "Trusted sites" in Windows Explorer.

1) On the Internet Explorer Tools menu, select Internet Options > Security > Trusted sites > Sites, and then clear the Require server verification (https:) for all sites in this zone check box.
2) In the Add this website to the zone box, type the address of the GX/GP GO to, and click Add > Close > OK.