When I try to validate my page I get this error:
Don’t know how to decode Content-Encoding ‘none’
I checked 2 different Grav sites and I didn’t get that error, so it’s not something Grav-specific but might be related to your theme.
Check https://www.google.com/search?q=Don't+know+how+to+decode+Content-Encoding+‘none for some resolutions of this error.
Theme is antimatter, I did not modify Grav, just installed and tried to check
is it safe to remove this line “header(‘Content-Encoding: none’);” from system/src/Grav/Common/Grav.php?
The solution was to enable gzip in Configuration