problem observed on enwiki and hewiki. probably exists elsewhere.
- in internet explorer 8 or 9, use Tools => Internet Options => Advance, and mark the checkbox "Display notification on every script error".
- Activate "Compatilbility mode"
- Open main page in hewiki or enwiki
WHAT WILL YOU SEE
- you get an exception on call to mw.centralNotice.initialize() (mw.centralNotice is null at the time this code executes)
- you will get consecutive exceptions that depend on which wiki is it
- if you log in to your account, many of your preferences will not be respected. e.g., if you enabled the "navpop" (aka "popup") gadget on enwiki, it will fail to work.