I'm using a search server 6.5.1 which is resulting in a 400 Bad request response on the POST request to http:///en-US/splunkd/__raw/servicesNS///search/parser.
Strangely this is not happening on two other search heads that I have in the cluster.
As a response in the browser response
{messages: [{type: "FATAL", text: "Invalid query."}]}
This is disabling user searches from the search server. I tried a couple of restarts to the search server but it didn't work.