I've tried to update to 7.1 and the upgrade reports as successful, but I get an error on the Host and Admin site settings pages. "Object not set the the reference of the object".

There is a page error in IE:
Message: Object doesn't support this property or method
Line: 5042
Char: 5
Code: 0
URI: http://website.org/DependencyHandler.axd/76bd2548876c9843312b847d629ebd84.54.js

How to I fix this?

I've rolled the site back to 6.2.1.

Thanks