I've just run the installer to upgrade from 2.3.1 to 2.8.1

Now when I try to go to the Control Panel (admin.php), I am redirected to


Which gives the "Disallowed Key Characters" error.

1 Answer 1


Turns out this is a known bug with 2.8.0+, affecting users with uri_protocol configuration setting set to ‘PATH_INFO’.

There is a patch available here:


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.