When uploading files with non-ASCII characters I get UnicodeEncodeError:
Exception Type: UnicodeEncodeError at /admin/studio/newsitem/add/ Exception Value: \
After investigating this some more I found out that I hadn't set the charset in my main Nginx config file:
http { charset utf-8; }
By adding the above, the problem disappeared and I think that this is the correct way of handling this issue.