Didn't manage to post a screen shot, but this happened on this very thread when I started to scroll down it to look at the replies.
The problem is that any action seems to have no effect. You cannot go back. You cannot always close the error message box. The only button that does something is the Debug script button. The system freezes. Sometimes if you wait everything unfreezes, but often the only way to get out is to use Task Manager and shut down the browser.
Here's what's in the error message box:
Warning: unresponsive script
A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue
secure-ds.serving-sys.c...urstingScript/SZMKFLVPAIDBR.js:27
[Box] Do not ask me again
[Buttons] Continue Debug script Stop script
The same message (with the same script listed) comes up on other threads in the United forum, but strangely not in the Trip Reports forum.
Edit: I cannot give you the complete script without the thing transforming into a URL link and replacing some of the text with an ellipsis. Simply add Http:// in front of the text quoted above.