Steps to reproduce:

• In a job a svg image is created by python/matplotlib (see attachment).
• The image is copied by the copy artefact plugin
• The image appears all black if viewed with firefox (version 42 or 43)
• jenkins is running on https

Changing the firefox preference security.csp.enable from true to false fixes the problem.

This seems to be related to this: https://greasyfork.org/de/forum/discussion/353/doesnt-work-because-of-content-security-policy
https://developer.mozilla.org/en-US/docs/Security/MixedContent/How_to_fix_website_with_mixed_content