hi dear customer, seems your firefox version does not support to override value for “xpinstall.signatures.required”.

To try Cisco Web Communicator before the review passed, you can follow below steps:

1. Download Firefox Developer Edition fromhttps://download.mozilla.org/?product=firefox-aurora-latest-ssl&os=osx&lang=en-US
2. Open the firefox developer edition, go to about:config, change value of “xpinstall.signatures.required” to False
3. Install Cisco Web Communicator from https://addons.mozilla.org/en-US/firefox/addon/cisco-web-communicator/

Contact us if any questions, thank you