Some possible causes I think:
1. They could have been using the same code for 3dvia Scenes and over time as they updated the player the code got more and more outdated (most likely since 3dvia player has almost no visual difference than last versions)
2. It could be a server error (evidence: IE never connects, we had a server breakdown a few months ago, models only add sometimes on the exact same settings)
3. It could be new coding (not as likely because there is no visual difference, but still could be because developers tried to solve a problem and got rid of something important)
4. Maybe a security error (now I don't know much about 3dvia's code, nor do I know anything about SSL, but it could be either. It could also be Scenes detecting if something is malicious. However, I did a test and determined that Microsoft Security Essentials is NOT causing the problem). BTW I'm learning PHP right now
5. The page might not be communicating with the plugin (Scenes is made up of both html and the plugin. The Scene itself is plugin, the design scene/chat is HTML. Obviously the plugin is not communicating with the page, just delete the tutorial sign then look in included models to see why. But the page must be communicating something with the plugin in order for it to work sometimes HOWEVER maybe it could be sending the wrong message sometimes or something along those lines as I am no expert at plugin->HTML and back communication)
6. It could be client side errors (think about cookies and similar stuff)
7. It could be server side errors (information in databases and stuff being modified on the internet, same problem as cookies)
8. It may be studio (Maybe these are general errors or parts of code were discontinued in this version of Studio?)