It means that the EXE is somehow detected to match what other users have flagged/voted as having some risk - although not detected as doing any harm as matching a virus signature. More information is here:

https://community.norton.com/en/forums/clarification-wsreputation1-detection

This was the first hit from a search-engine search phrase: "WS.Reputation.1" norton

The article also explains how Yamaha may go about submitting their program for the whitelist so this, what is likely to be a false positive, does not occur.

There is a slim chance that something else (not this program) has infected your computer and has modified the EXE from its original form. To cover this possibility - if it were me - I'd do a few things:

1) Submit the flagged EXE to a few different antivirus (online) scanning tools to see if a true virus signature is detected.
2) Scan my system for malware with something like malwarebytes or whatever the wider security community now considers to be the best utility (or suite of utilites)
3) If possible, download the file again in a "clean" environment and compare the clean downloaded file with the file that is being reported by Norton. If they match - then it is very unlikely you are dealing with a true virus and more likely it is a false positive from the antivirus software.

A better forum for this kind of support would be something like the norton forums, or bleepingcomputer.com, or ...