Google Chrome has disabled all NPAPI plugins, including the Unity Web Player. To continue playing Unity Web Player games you’ll need to switch to another browser like Firefox or enable NPAPI in chrome.
To re-enable NPAPI plugins and get some more time with Unity Web Player games on Chrome:
1. Enter chrome://flags/#enable-npapi into your address bar.
2. Click Enable under Enable NPAPI.
3. Restart your browser and Unity Web Player games should work again until Chrome disables it completely.