I set up wordpress multisite on my site a little while ago(about a month)... and recently google has started handing me internal server error 500 responses for my pages when it trys to crawl them.
Around the same time I got this response from W3 total cache
Recently an error occurred while creating the CSS / JS minify cache: No sources to serve
No clue what that means... I've searched on here and it seems to be generally unknown.. the only responses I have seen from devs were "this will be sorted in next version" but they were posts from 9 months ago...