When following links from a MailChimp campaign that contain tracking code, I get:
The URI you submitted has disallowed characters.
I have narrowed down the error to a % character making up an html entity (?) equivalent for an ampersand.
The percent sign in the url causes this error. Is there a way to allow it in the url?
[edit]
I should mention that I am running EE 2.5.2 and all extensions are disabled.