If your network environment already supports the proxy servers that are compliant with the HTTP 1.1 protocol or later, you can disregard this entry.

After you have tried to download LiveUpdate for the first time, the following message might appear:

"LU1863: Insufficient free disk space
There is not enough free disk space for LiveUpdate to operate properly. Please free up disk space on your computer and run LiveUpdate again."

You might have insufficient disk space. However, it is much more probable that this message appears in error because the proxy server is unable to send the correct Contents-Length header field.

This error message might appear on Symantec Endpoint Protection Manager, a Symantec Endpoint Protection client, or a Symantec Network Access Control client.

You should verify that the disk drive to which you downloaded LiveUpdate has sufficient disk space. If you verified that the disk drive has sufficient space, then most likely a proxy server caused the problem.

If a proxy server receives an HTTP reply that does not include a Content-Length header field, then the above-listed message erroneously appears. The erroneous message appears on the computer on which the LiveUpdate has been downloaded.

The proxy servers that are compliant with HTTP 1.1 protocols automatically include Content-Length header-entity fields. The proxy servers that are compliant with HTTP 1.0 protocols do not automatically include Content-Length header-entity fields.

You should ensure that the proxy servers in your network are compliant with the HTTP 1.1. protocol.

Now we need to look at how to make a proxy server compliant with HTTP 1.1 protocols. The answer here is that the configuration differs from the Proxy software/device we are using. For example if we are working with Microsoft ISA Server this link should help

Reference: "Readme.txt" from "Symantec_Endpoint_Protection_11.0.4000_MR4_AllWin_EN_CD1",</pre>