You have configured your Symantec Network Access Control (SNAC) Gateway Enforcer to allow Windows clients that connect to your network to automatically download the On-Demand Client (ODC) for Windows. However, when users connect to the Gateway Enforcer and use Internet Explorer 11 or the new browser introduced with Windows 10, Edge, the On-Demand Client does not download automatically, and the download fails.
The Symantec Network Access Control On-Demand Client for Windows does not support the use of Internet Explorer 11 or Edge for an automatic download.
Symantec Network Access Control reached End Of Life (EOL) in late 2014. The last version released was 12.1.5 (12.1 RU5). For details on EOL, click Related Articles.
To work around this issue, you can manually download and install the On-Demand Client for Windows with the browser.