Flash Player error messages from browser?

Hello.

So a client I’m building assorted things for gets these annoying error dialog boxes popping up in web pages that I never see myself. But they are akin to those I would see if I were running a SWF locally from my hard drive in my Flash Player. I’ve tested for these errors repeatedly on different servers and different computers and am coming to the conclusion that there is something peculiar about the way their Flash Player in their browser(s) is configured. Have they somehow installed a debug mode of Flash Player? Have they turned on some annoying verbose mode? If so how do I tell them how to turn it off so that they can realize that the way things look in their office are not remotely representative of the way Flash is rendering things on 95% of the computers in the world (and 100% of the computers I have tested things on)?

Thanks for your time.