Can't access shell at /shell

[jacobparis]

I can start dynamodb locally and it all works fine -- everything as expected

However if I navigate to http://localhost:8000/shell it returns Error 413 and the console running dynamodb-local prints out this:

2019-05-02 14:35:25.767:WARN:oejh.HttpParser:HttpParser Full for SCEP@6add4393{l(/127.0.0.1:52861)<->r(/127.0.0.1:8000),s=1,open=true,ishut=false,oshut=false,rb=false,wb=false,w=true,i=0r}-{AsyncHttpConnection@78033d69,g=HttpGenerator{s=0,h=-1,b=-1,c=-1},p=HttpParser{s=-1,l=5681,c=-3},r=0} 

A few weeks ago when I started, I was successfully able to use the shell, but since I only use it for deleting tables (the reason I want to use it now) I can't speak as to when it stopped working or what changes I might have made that broke it.