Read character data where <results> or <response> was expected

[Skrub]

Hi

I'm using .Net (Splunk.Client) to search splunk data (firewall logs). Code is similar to this:

using (SearchResultStream stream = await service.SearchOneShotAsync(search))
{
  foreach (SearchResult searchResult in stream)
  {
     string src_ip = searchResult.GetValue(searchResult.FieldNames[0]);
     string dst_ip = searchResult.GetValue(searchResult.FieldNames[1]);
     string port = searchResult.GetValue(searchResult.FieldNames[2]);
     string protocol = searchResult.GetValue(searchResult.FieldNames[3]);
     result += src_ip + "," + dst_ip + "," + port + "," + protocol + "\r\n";
   }
Console.WriteLine("\r\n");
}

My query takes the expected time to complete (around 75 minutes) but when parsing the result it throws an exception: "Read character data where <results> or <response> was expected".

I'm using the same query string on different search indexes. Only one of them fails, the others are working just fine.

Any idea what could be causing this? What's the meaning of this error? Can't find it documented anywhere.