title: ProtocolException: Expected ':status' header not present
body: <p>Retrofit network calls fails with a Protocol Exception suddenly in a working app.
  The app was working till yesterday and today all the network calls fails. The calls works fine with HTTP but fails with HTTPS.</p>
  
  <p>Here is the logs,</p>
  
  <pre><code>java.net.ProtocolException: Expected ':status' header not present
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.Http2xStream.readHttp2HeadersList(Http2xStream.java:262)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.Http2xStream.readResponseHeaders(Http2xStream.java:145)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.CallServerInterceptor.intercept(CallServerInterceptor.java:53)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at codmob.com.campuswallet.app.ApiClient$1.intercept(ApiClient.java:66)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:45)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:109)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:124)
  10-18 14:59:01.103 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:170)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at okhttp3.RealCall.access$100(RealCall.java:33)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at okhttp3.RealCall$AsyncCall.execute(RealCall.java:120)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
  10-18 14:59:01.104 30746-30746/? W/System.err:     at java.lang.Thread.run(Thread.java:761)
  </code></pre>