com.netflix.feign NullPointerException in Response class

Question

I have a problem with Feign Clients. I have three modules which communicate with each other using feign. It looks somehow like this:
moduleA <---feign---> moduleB <----feign---->moduleC
My problem occurs when moduleC is sending successfull response to moduleB. I annalyzed feign-core classes and have found a cause.

 package feign;
  public final class Response {

  private final int status;
  private final String reason;
  private final Map<String, Collection<String>> headers;
  private final Body body;

  private Response(int status, String reason, Map<String, Collection<String>> headers, Body body) {
    checkState(status >= 200, "Invalid status code: %s", status); //my status is 200
    this.status = status;
    this.reason = checkNotNull(reason, "reason"); // my reason is unfortunatelly null
    LinkedHashMap<String, Collection<String>>
        copyOf =
        new LinkedHashMap<String, Collection<String>>();
    copyOf.putAll(checkNotNull(headers, "headers"));
    this.headers = Collections.unmodifiableMap(copyOf);
    this.body = body; //nullable
  }
}

In feign-core class Response when method checkNotNull(reason, "reason") is triggered there goes NullPointerException even though the response status is 200. How can I fix it?

EDIT: My feign version is 8.1.1

EDIT2: My tomcat version is 8.5.20

Answer 1

I have found the answer. Problem was caused by tomcat. Version 8.0.* disabled reason phrase in response, therefore I had to enabled it (fortunatelly it was still possible because in versions above 9 it is not). I had to edit server.xml file and append to Connector sendReasonPhrase attribute. Now it looks like this:

<Connector port="8080" protocol="HTTP/1.1"
           connectionTimeout="20000"
           sendReasonPhrase="true"
           redirectPort="8443" />

Here is more about an issue and here is more about Connector attributes