I can no longer edit my home.php page!!

To update my homepage I always went to the dashboard and them under Appearance clicked on editor. Next I would go to the home.php option on the right and then I was able to edit info on my front page of my website. Now when I click on home.php the box won’t come up and it says that the server isn’t responding. I can still edit my pages just fine but can’t edit my front page which is really stressing me out!! Please help!!

Thank you!!