Script errors happen because people that write web sites don't always do it
right.
You can send a message to the webmaster of the site to tell them about the
problem and see if they will fix it.
Or, you can do the tools, internet options advanced and take the check out
of the box to be informed of every script error, and put a check in the box
to disable script debugging, and you won't have to see a report on every
minor error in a web page that you can't do anything about anyway.