RC2 directly update to 3.9 final or reinstall?

Once it is released, can I update CIS 3.9.75615.502 RC2 to 3.9 final directly or do I need to uninstall the RC2 and then reinstall CIS 3.9 final?

recommended to do a complete clean install.

Answer from umesh
Xman 8)

Seems that something is going weird on UpdatePath. Tomorrow, may/14 we will have some news. For awhile, if you can’t update AV DB, just use “av/updates39” and you will get 1160 DB. I had this issue in a clean install + importing rules from RC2 and this trick worked.