Download.gz files downloads when you try to access the homepage url of your website. So I was wondering what is this file, at first I thought it is a virus. The download.gz appeared first when I had installed a cache plugin called W3 Total Cache Plugin. So when I deleted it I realized the error when I am trying to access the homepage.
It can be frustrating especially when you see these types of errors. A file named download with an extension .gz
How to solve the error
After doing my research, I realized all the methods stated do not work, so I had to access the back end of my website and deleted a file named w3tc. And my website worked. It took me almost an hour to find this solution.