I just experienced an HTTP internal error code 500 after renaming "econature" in "/home2/yourfrf1/public_html/sites/self-inquiry/wp-content/themes/econature/" to "econature2" via cPanel.
I did this because when I tried to update the theme under Appearance> Themes, it failed because it said that it already existed. I was afraid to delete it, so I renamed it so that I could upload the new theme. But after renaming it, I am getting this error, so I changed it back to "econature" and that fixed it. But how am I supposed to upload the new theme if the destination already exists?