If the Unity Web Player fails to load and instead you see the message ‘Failed to update Unity Web Player’ then the domain *.unity3d.com may be blocked. Your firewall or proxy server may be preventing access to this domain (website).
IntoScience and Unity requires that this domain be accessible so the web player can check version information.
Solution: Allow access to all domains and sub-domains at unity3d.com. If you do not have admin privileges then you may need to ask your IT administrator or manager to perform this change.