Hi, I just got the following error for my Redmine 3.0.0 installation:

ERROR MESSAGE:

ActionController::UnknownFormat: ActionController::UnknownFormat

WHERE:

issues#show

app/controllers/application_controller.rb:238
app/controllers/application_controller.rb:266

URL:

https:///issues/353.pdf

BROWSER:

100.0%  Googlebot 2.1 ()


FULL BACKTRACE:

[GEM_ROOT]/gems/actionpack-4.2.0/lib/action_controller/metal/mime_responds.rb:218
app/controllers/application_controller.rb:238
app/controllers/application_controller.rb:266
[GEM_ROOT]/gems/activesupport-4.2.0/lib/active_support/rescuable.rb:80
...

The problem arises when a user that is not logged in tries to retrive the PDF export of an issue, which is not allowed in our configuration. It seems for me that the method @require_login@ in @application_controller.rb@ is missing a case for the PDF format.