I can vouch for Mark as we're both working on same site.
Solr & Job Scheduler are running exactly as per the installation guide on c: drive, we've put the site on a separate e: drive, database on a seperate VM (web server is also a VM).
Theme was left as Fiji.
We decided to install a fresh site and database, creating a new "blank" site and new database without the config_override, thus without Job Scheduler - all worked worked fine (as in site shows up on web browser, can log in, out etc etc).
Gonig back to the original troublesome and restored site, we deleted the contents of the file storage area from the recovered site, deleted the config_override, stopped the Job Scheduler in Services, then copied across the web contents from the "blank" site except the db connection string which we left as the original and "undamaged" database.
The site suddenly worked, all content and group settings test blog posts etc intact.
We then restored the config_override, started up Job Scheduler and still everything works fine.
It's a head scratcher this one!