1610768 - DistributedCOM warnings (10016) appear in Windows 10 Event Viewer on startup and when visiting sites with videos

Status: NEW

(Core :: Audio/Video: Playback, defect, P3)

Description

[Kestrel]

STR:

1. Open Windows 10 Event Viewer.
2. Start Firefox.
3. Refresh Event Viewer.

Two DCOM 10016 warnings appear:

The application-specific permission settings do not grant Local Activation permission for the COM Server application with CLSID 
{2593F8B9-4EAF-457C-B68A-50F6B8EA6B54}
 and APPID 
{15C20B67-12E7-4BB6-92BB-7AFF07997402}
 to the user <USER> from address LocalHost (Using LRPC) running in the application container Unavailable SID (Unavailable). 
This security permission can be modified using the Component Services administrative tool.

The CLSID and APPID correspond with the RuntimeBroker. More of these warnings appear when visiting sites that have videos such as youtube.

Regression range:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=383f32cdb53bf9d3ce638dfaff490794758bbf0a&tochange=303a1f4c20e8d4fadb267a97573ea672f56279f6

Regressed by Bug 1521370.

Comment 1

[MarkRH]

I've been getting these ever since I updated from Windows 7 Pro to Windows 10 Pro which was 1903 at that time (now 1909). I thought it was just some Window 10 issue due to the upgrade over Windows 7 and went through all kinds of things to fix it. Event 10016 seems to be a common thing when Googling it.

But, yeah, I can reproduce this with Firefox 72.0.2 and previous versions.

Comment 2

[Alastor Wu [:alwu]]

Hi, jya,
Any thought about why bug1521370 causes this issue?

Comment 3

[Jean-Yves Avenard [:jya]]

(In reply to Alastor Wu [:alwu] from comment #2)

Hi, jya,
Any thought about why bug1521370 causes this issue?

IIRC, prior this bug the COM interface wouldn't have been explicitly initialised on some threads. To use WMF, you must use a thread with COM initialised.

With bug 1521370, on startup we initialise thread for COMs and attempt to initialise the VP9 MFT.
However, 2593F8B9-4EAF-457C-B68A-50F6B8EA6B54 isn't anything to do with the services we load.

A search reveals similar set of reports, not related to Firefox.

not sure what this service is. But I'm assuming this to be harmless, and documented by Microsoft as being expected