Basically, customer mention that when they have their JIRA setup with Apache proxy and SSL the what's new content (some may call it the JIRA welcome page) in JIRA 6.0.1 will not be shown.

Steps to reproduce

1. Setup JIRA with Apache proxy and SSL
2. Access JIRA with one new user which has never login before (via IE10 or Google Chrome internet browser)
3. The What's New Content (JIRA Welcome page) will show something like below:
   

According to customer analysing:

This seems to be an issue with the linked iframe content that is redirected to content that is http. Since it redirects from https to http back to https, the internet browser wont show it as http is considered unsecure Iframe content.
Please refer to the following screenshots: screenshot-1.jpg and screenshot-2.jpg