UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36

Example URL:
https://jazz.net/jts/composition/jaas.css

Steps to reproduce the problem:
1. Go to https://jazz.net/jts/composition/jaas.css, it loads
2. Refresh page and see 500 error
3. Refresh page again, it loads. 

What is the expected behavior?
The css file should load on every page refresh. 

What went wrong?
According to the specs here: https://tools.ietf.org/html/rfc7232#section-2.3 the ETag should be surrounded by quotes. Chrome is sending back the ETag with no quotes and this strictly compliant server is failing to respond to requests. 

Did this work before? N/A 

Chrome version: 51.0.2704.103  Channel: stable
OS Version: OS X 10.11.5
Flash Version: Shockwave Flash 22.0 r0