This error message is just priceless:
I love the title. It's really wonderful. "Problem occurred." You know, I did figure that out. I figured it out because an error message is being displayed.
"Unable to create the selected preference page" - this is basically the only helpful message for users on the entire box. And it's not very helpful because once you close the dialog, the same text appears in the preferences dialog anyway, making the error dialog practically worthless.
But wait, what's this? It offers details! Except the details are the exact same text from the error dialog, minus "Reason."
So what causes this dialog? I have no idea. I can make a guess, though. "org/eclipse/ui/IWorkbenchPreferencePage" is the fully qualified name of an interface. Presumably this was caused by a Java exception, most likely either ClassNotFoundException or NoClassDefFoundError.
Unfortunately I, as developer, have no way to know. It doesn't show the stack trace anywhere (it's not logged and not dumped to the console). So ultimately I have no idea what causes this error.
To add insult to injury, I can't even duplicate it on the machine I took the screenshot from. It just randomly stopped happening. It's some form of classloading error, I think, but I have absolutely no way of knowing.
Sigh.