Disappering shell promt in Git Bash

Hi there!
During the working on Lingua Franca project I found a thing that is unclear for me.
I was working on task 14:
and I tried to run commands from the solution code separately. But after I’d typed the part after pipeline ( grep 0 > todo/empty_files.txt) the shell promt disappeared and I was disabled to run any of the command.
Could anyone please explain why did it happen?
Thanks in advance!

Is this your entire command? What did you pipe to grep? You might want to link the project and explain what your task is an how you have attempted to accomplish it. With just that line I can see why it would appear paused but if you piped something then the details of what you piper matter.