Text no longer shows after killing program, using tmux

I'm running a Minecraft server and whenever I "sh rtoolkit.sh" to start the server, everything works fine however once I stop the server and return to the command line ready to enter a command, text I type doesn't show up and the cursor remains in the same position, yet if I enter a command and hit enter, I see the result. For example ls doesn't show up when I'm typing it, but after hitting enter I see the output. I've tried clear, but still the same problem.

The only way I've found to fix the issue is to kill the current tmux window and re-create it.

I'm doing all this over SSH from Mint.

Your description indicates that the tty was left in a non-echoing mode after you stopped the server.
This often happens when an “interactive” program exits unexpectedly and does not have a chance to restore the various tty modes it adjusted when it started. If it happens regularly when exiting the program normally, then there is a bug in the program.

You can probably reproduce the effect with a command like this:

stty -echo ; printf 'Type something (there will be no echo); Enter/Control-C to resume...' ; read ; echo

You should be able to use this command (typed “blindly”; since there is no echo) to restore normal tty functionality:

stty sane