Tested and is still a problem in 1.14.2.
I used a method detailed in https://www.youtube.com/watch?v=sd8SM8YWP9U
This just occurred for me on 1.9pre3, I did an f3-c crash-dump. Should I submit here or open a new bug?
Running on a local server (127.0.0.1) while running two instances of minecraft, dropped items only showed as stone for one of them.
Still a problem as of 1.15.2 on Windows 10
For example, when sending the command "op" with no accompanying username the following is returned
"Unknown commandop<–[HERE]"
When it should be
"Unknown command
op<--[HERE]"
This is very troublesome when executing commands that return a large number of lines, that are then not separated by line-breaks as they would be in game, or in the server console itself