White box appearing on screen

The thing that is interesting to me is that Flash Player is a browser plug-in, meaning that it runs in a web browser.  The web browser would generally take up the whole screen, not a small corner of it.  We wouldn't just pop our own little window up in the corner like that.  There's a parent application involved that isn't us.

My sense is that this is a third-party application that's embedding Flash Player in its own window.  If I had to guess, this is probably older software, designed for Windows 7 and below.  It's probably not something that came pre-installed or came from the Windows app store.

Given that it's popping up in the corner like that, I'm thinking that it's something that issues notifications, like an instant messaging client (AOL Instant Messenger, Yahoo Messenger, etc.), or maybe something related to a game?  Old versions of Quickbooks maybe?

There are no useful clues about what the parent application might be, since it's just a white rectangle.  It's possible that recent security-related changes caused whatever this is to stop working ("Movie not loaded" indicates that the application attempted to load some Flash-based content that upon inspection, either failed a validation check - e.g. the data itself is malformed, or we thought it might be malicious and declined to run it).

Without knowing what that application might be, I don't have any good guesses about what to do about it.  This is the first complaint I've seen about this, so I don't have a list of common suspects.

Please provide the following information:

• Operating system version
• Web browser and version
• Flash Player version
• A direct link to a web page that demonstrates the problem
• If you get error messages, please provide a screenshot