I've been supplied with a webfonts kit from myfonts in order to load a specific non-standard font onto a website.

No actual otf or ttf files were supplied, just eot, svg, woff and a css.

The css stylesheet contains the fonts base64 encoded as huge strings.

Problem is that this results in a nearly 2mb .css download!

I read that it's more efficient to link to the otf files directly and since I didn't have those, I used an online converter to decode the strings and saved the result as .otf

That seemed to work and really cut down the size, then i got this warning in safari:

Could this be because I used the online converter to create the otf file or will it always happen when linking directly to the font file?