It looks like the Settings icon for the Chrome Control no longer displays in SharePoint Online

[Paul Katz]

We make use of the Control Control for our SharePoint Add-Ins, and it looks like the Settings icon for the upper right menu is now missing. On further examination, the URL for the image https://<redacted >/apptest/_layouts/15/defaultcss.ashx?ctag=1522964650769&resource=spcommon returns a SharePoint error screen.

Any chance anyone else has had this issue with their Add-Ins? I suspect some of the underlying shifts in SharePoint Online's UIs may have broke the Chrome Control capability, and I'm hoping someone on the SharePoint team could investigate.

[#2]

As a follow-on, I'd be happy to demonstrate the issue to any SharePoint engineer that needs to see it.

[#3]

Recently from last few weeks, we have the same issue. Not able to see a setting icon in chrome menu header for SharePoint online add-in.

On defaultcss.ashx reference link, it giving sharepoint exception