Remote interpreter reporting 'badMessage: 400 for HttpChannelOverHttp'

I want to use Zeppelin locally to develop in Python, but have the code run on a server interpreter. I have created a new Python interpreter locally called pythonserver, and added the hostname and port of my server, and selected 'Connect to existing process'. Most of the other configuration file settings on server and client are the defaults. Shiro is active with a few cleartext user/pass, but anonymous is allowed.

I have a single cell on the local Zeppelin install that uses the remote python interpreter:

%pythonserver
print('asdf')

Running this cell causes the following to display in the server log file:

WARN [2019-01-25 16:06:58,073] ({qtp853993923-87} HttpParser.java[parseNext]:1344) - badMessage: 400 for HttpChannelOverHttp@5c8828f1{r=0,c=false,a=IDLE,uri=}

 
 
On the client Zeppelin UI, I see the following error:
org.apache.thrift.transport.TTransportException at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:132) at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86) at org.apache.thrift.protocol.TBinaryProtocol.readStringBody(TBinaryProtocol.java:380) at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:230) at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69) at org.apache.zeppelin.interpreter.thrift.RemoteInterpreterService$Client.recv_createInterpreter(RemoteInterpreterService.java:209) at org.apache.zeppelin.interpreter.thrift.RemoteInterpreterService$Client.createInterpreter(RemoteInterpreterService.java:192) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter$2.call(RemoteInterpreter.java:169) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter$2.call(RemoteInterpreter.java:165) at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess.callRemoteFunction(RemoteInterpreterProcess.java:135) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.internal_create(RemoteInterpreter.java:165) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.open(RemoteInterpreter.java:132) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.getFormType(RemoteInterpreter.java:299) at org.apache.zeppelin.notebook.Paragraph.jobRun(Paragraph.java:407) at org.apache.zeppelin.scheduler.Job.run(Job.java:188) at org.apache.zeppelin.scheduler.RemoteScheduler$JobRunner.run(RemoteScheduler.java:307) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)