
The file however opens up right after the error message anyway.
The error suddenly occurred when I opened up the file with a Firefox update window popping up right after the error message.
Technical info:
* Firefox 2.0.0.7 (Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.7) Gecko/20070914 Firefox/2.0.0.7).
* Adblock Plus 0.7.5.2.
* Windows XP Pro (updated).