Have you seen Product Update - What you need to know?
Note: If Nintex Workflow for Project Server 2010 is installed in the same environment, restart the "Microsoft Project Server Queue Service 2010" service and do a final IISreset on each server.
For instructions on activating Nintex Live Catalog, see Installing Nintex Workflow 2010 and Nintex Forms 2010.
Is there any impact to workflows that are still running when you do an update to a newer release version? I have 2010 that is an older version and I want to upgrade to 2015 July 22 release version for 2010. My concern is for workflows that may still be running when I upgrade.