It always helps to keep a copy of FH! Just install again in a different folder, then locate the original file you were editing. A fast way would be to go into the FH folder, go to the search bar, and search "grass". Find the one you tried to edit, and then copy and place it where the original used to be in your actual FH folder.
Once finished, you can delete the backup FH folder if you want to.
I hope this helped!