The instructions for setting up the reverse proxy outline steps to modify the httpd configuration to disable AsyncSendFile for the reverse proxy's cache folder. This configuration is needed to prevent crashes that can occur when the cache is updated with new files.
Modify httpd.conf to only enable Asyncsendfile for the Inetpub/Content folder.
Make the following changes to httpd.conf:
Locate the following line, and add the character # to comment it out, as shown: #AsyncSendFile anydirectory
Locate the following lines and remove the character # to uncomment them, and make the following change, where SEPM_Install is the actual path of your Symantec Endpoint Protection Manager installation (use forward slashes). AsyncSendFile givendirectory ForceAsyncSendFile "SEPM_Install/Inetpub/content"
These steps are also outlined in the following document: