Thread:Project:Support desk/File extension does not match MIME type when uploading Adobe Illustrator (.ai) files/reply

For me the solution was

Just checking the mime-type

benny@web:/var/www/wiki.open-laboratory.de/htdocs/includes# file Image.ai -i Image.ai: application/pdf; charset=binary

So the mime type is application/pdf

Just added in the mime.types

application/pdf pdf ai

and done ;)