Norton removes Fantasy Ground 2 install upon update

I have Norton Security v.22.9.3.13.  I can install a licensed version of FG2 from http://www.fantasygrounds.com 

and install the product.  As the installer attempts to update the program, Norton stops the update and removes the installation without any consultation.  This is based on WS.Reputation.1--apparently the update file has been given a "Bad Reputation" rating by "Few Users" among Norton customers.  Can't find out what has caused the program to be deprecated. 

How reliable is this opinion-based rating system, compared to actually finding a malware signature or heuristic issue with the program itself?