latest web update requires update (see image for details)

just installed unity web player, and updated it twice, manually:

^sorry if you can't read the error

my browser reports the plugin to be the latest, but the plugin somehow doesn't recognize itself as being the latest...

 

So, there are two components (well, three, but we can ignore one of them.) The plugin is what links the browser to the Unity runtime code. The status you show is the plugin status. You have 4.5.2f1 which is pretty recent. When you visit a page that hosts Unity content, the plugin will look at the version of Unity the content was made with, and download the correct runtime code. The failure you get is the plugin not being able to download the player component. A little bit of detective work tells me that the game itself was authored using Unity 3.5.3f3. The player that the plugin tried to download was 4.3.7f1, which is the most recent stable player. I can't explain why the download of this critical component failed. A common cause is that a download manager has intercepted the Unity request to fetch this file, and has prevented Unity plugin from receiving it.