Setting MIME in .htaccess results in Internal Server Error..

Hello folks,
I was trying to fix a problem with the MIME type of SVG files on my site, I
don't have webmaster access, so I was attempting to fix the .htaccess file
as described in various documents.

When I put the .htaccess file containing the following:

AddType image/svg+xml svg

in the directory containing the svg files, when I open an svg page, I get
the Internal Server Error 500 as a result.

Anyone who can explain what's wrong ?

I edited the file on a win machine and put the file on servber using ftp in
ascii mode.

TIA

Flavio