I've installed wp multisite. Since then I cannot download .zip files with the media uploader. I get always that warning :
“myfilename.zip” has failed to upload due to an error
Sorry, this file type is not permitted for security reasons.
What should I do to fix that problem?
remark: it does not seem to be a problem with my hosting (Bluehost) since I have the exact same problem in local (MAMP)