Changing to Custom Paper Size

Uploaded the new version 9.9, but now can't get the custom page size to work.  It always defaults to the fixed.  Is there a way to accomplish this.  Plus whenever I hit the shortcut, it says the path is wrong, then sends me there anyway.

Really need to push a project through today with a custom size.  Would greatly appreciate any help on how to do that.

Thanks in advance.