css-optimization

Optimize CSS files - file not found

In the performance settings when Optimize CSS files is selected, I get a 404. The reports section shows a 404 for example sites/default/files/ctools/css/588b003a48050c4e59cbeba2b453cb92.css not found. I have the site running on a Mac without any issues. It's on Ubuntu. It's not a permissions issue (files dir and sub dirs have chmod 777...