I added the MIME type with an .htaccess
AddType text/xml .scml
AddType text/xml .scon
And tried also to add the MIME type directly in Apache mime.types.
Both are working, because when done, Chrome displays this on top of page :
"This XML file does not appear to have any style information associated with it. The document tree is shown below."
I think it's fine if the .scml is recognized as a XML file.
However, my spriter animation is still broken (same : invisible sprites, dissassembled parts, no animation) after export on the host (but works fine in Construct 2)
Do you have an idea where it comes from ?