I just downloaded the 2.2.3 update, and I had the same problem I had with 2.2.1:
I am currently using a MacBook Air OS X 10.11.4, with Safari 9.1.
When I open a particular QuickTime (.mov) video, I get the following pop-up error message:
"Codec not supported
VLC could not decode the format "XiVs" (No description for this codec)"
The video seems to be playing just fine, though; all I have to do is close the pop-up. (Perhaps there is some special feature I wouldn't be able to access?) If the video is looping, however, the window has to be closed manually every time it restarts, which makes the video essentially impossible to watch.
In a previous discussion, another user asked about disabling this pop-up - since the video is actually playing! - and was told that "this dialog only pops up for serious errors". I appreciate that, but if the video is playing fine for a regular user who basically just wants to watch it as is, and the issue is serious primarily for the developers, I still think there ought to be a way for non-advanced users to hide it, at least on a particular video. Unless it is sending out an automatic error report, it does you no good, and annoys me.