OPUS 12 freezes when selecting an AVI

When I open OPUS 12 with an empty Viewer Pane and click on an AVI, or Mp4 file Opus freezes and I am forced to close it with the Window's Task Manager. If I remember to hit the Show or Hide VP button before doing anything else everything is OK. I consider this a bug because up until now this extra step was never necessary.

At what point does it freeze? Is anything displayed in the viewer pane? Or in the title of the viewer pane?

Right now, when I open Opus the pane is white I first select my folder that holds all the AVIs and upon opening I click on the thumbnail a wish to play in the pane window. The pain window turns black with no image in it so I press on the avi file once more and nothing changes. At this point I discover the Opus has frozen on me and even an attempt to close on the Task Bar fails and I have to close OPUS with the Task Manager. Incidently, this does not happen with any other image or audio files; only AVIs and Mp4s.

Is anything shown in the viewer pane's title bar?

Yes, All the usual tiny icons are visible.
An interesting new observation: If I happen to open OPUS and another folder shows first (which has other files than AVI and MP4) and click on this other file which shows by its thumbnail before going to my avi folder, all works as expected. In other words, once I get OPUS started it will never freeze in this fashion. So I tried saving my setting in this other folder with the thumbnail showing in the pane window in hopes that this will fix my problem but alas, it didn't changeanything.

Another observation: When I stated above that the avi files will work once the window pane gets started elsewhere, now that proves to work just once. After the first avi thumbnail shows up in the pane nothing else can be done; OPUS freezes with an attempt to show a second avi.

If you go to Preferences / Viewer / Plugins and turn off the Movie plugin, then click OK, does the problem still happen?

If that fixes things, the issues is likely to be with a 3rd party DLL involved in video playback, and not in Opus itself.

If you still see the problem, try also turning off ActiveX + Preview + Office + Web to see if that stops the freeze. If so there are some other things we can investigate, but I'll keep things simple for now and wait to hear back.

Yes! Turning off the Movie plugin (which happens to be VLC) fixed it. Thank you.

By the way, is there anything that might potentially go missing elsewhere without the Movie plugin turned on?

What makes you say the movie plugin is VLC? Is that the icon it displays?

No, I have DAUM's PotPlayer set as my preferred player so for instance if were to switch to VLC (as I at times tend to do since neither of them are perfect for my needs) would my files not play in OPUS?.