Having the following error output trying to start, restart or do a configtest on Apache server?
Invalid command ‘ProxyPreserveHost’, perhaps misspelled or defined by a module not included in the server configuration
This is likely caused because mod_proxy module is not present or disabled. To enable it, look out for the following in the main server configuration :
"]LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so
Then you may attempt run a configtest and restart the Web server daemon.