Battlefield 4 Google Chrome users have been having issues with battlelog since they released there last update, the CTE is asking users to enable the browsers NPAPI which can been done automatically or manually so if you are having issues with Battlelog then you may want to try this.
When i logged into the Battlefield 4 Community Test Environment today i was greeted with the above popup (image) asking me if i wanted to enable the NPAPI for Google Chrome, at the time i was using Firefox not Google Chrome but i do have it installed on my PC so i clicked yes anyway.
In order to play Battlefield on PC using Google Chrome version 42 or later you must enable the NPAPI.
Do you want the installer to enable NPAPI for you?
If you choose YES you may be asked to shut down Google Chrome manually.
NPAPI is a web browser plugin technology currently used by the Battlelog Game Launcher Plugin and others. If you select NO you must manually enable the NPAPI interface option in Google Chrome under:
or use a different web browser to be able to play Battlefield on PC Battlelog.
So that is all good and well and may fix your issues for now but this approach will not work for much longer as the developers of Google Chrome are about to phase out the NPAPI plugin altogether.
Code running in an NPAPI plugin has the full permissions of the current user and is not sandboxed or shielded from malicious input by Google Chrome in any way. You should be especially cautious when processing input from untrusted sources, such as when working with content scripts or XMLHttpRequest.
Because of the additional security risks NPAPI poses to users, extensions that use it will require manual review before being accepted in the Chrome Web Store.