Summary

The following custom CSS styling applied to the sidebar within the Sidebar, header and footer under the Look and feel section used to work on Confluence Cloud.
However, it doesn't work anymore on newer versions of Confluence.

{style:import=https://example.atlassian.net/wiki/download/attachments/2129971/sidebar.css?api=v2}

Environment

• Confluence Cloud 1000.690.0

Steps to Reproduce

1. Step 1: Upload a CSS file sidebar.css to an arbitrary page.
2. Step 2: Go to Look and feel section > Sidebar, header and footer > Submit Style Macro like below.

{style:import=https://example.atlassian.net/wiki/download/attachments/__ID__/sidebar.css?api=v2}

Expected Results

• The CSS affects on pages

Actual Results

• Nothing happens on pages.

Notes

• CONF-41681 might be related to this problem.
• As written in Restricted functions in Confluence Cloud, CSS injection isn't supported on Confluence Cloud. However there is well-known workaround to apply CSS by using LOOK AND FEEL such as Editing CSSs in Confluence OnDemand.
• Atlassian keeps fixing the bug on this workaround such as CONF-44957.
• This might not be Style Macro import feature's problem but a Content-Type problem on attachment file. Now attachment file responds with text/plain header, but it possibly used to respond with text/css.

HTTP/1.1 200 OK
Accept-Ranges: bytes
Access-Control-Allow-Origin: *
Access-Control-Expose-Headers: Accept-Ranges, Content-Encoding, Content-Length, Content-Range
Cache-Control: private
Content-Disposition: inline; filename="sidebar.css"
Content-Type: text/plain
Date: Thu, 22 Dec 2016 00:44:14 GMT
Timing-Allow-Origin: *
x-b3-spanid: 830e54d871fb39f0
x-b3-traceid: 830e54d871fb39f0
Content-Length: 738
Connection: keep-alive

Workaround

• Write down CSS directly but not importing.