So it should come as no surprise that it won't work with the forthcoming macOS Sierra either.
In a service bulletin emailed to registered users of Desktop 8, Parallels advised:
Before you install macOS Sierra public beta or the full release, be sure to upgrade to Parallels Desktop 11 for Mac. It is our latest version that addresses known compatibility issues.
BONUS: When you upgrade to Parallels Desktop 11 you automatically qualify to get our next version of Parallels Desktop at no additional cost to you.
The current price of an upgrade from Parallels Desktop 7 or 8 to 11 is $64.95, but a new licence with upgrade rights to version 12 is available via OndeSoft for US$39.99 ($53.05) when combined with any other item. OndeSoft has deals priced as low as US$1 so there's a useful saving to be had.