Just setup a brand new installation of OCS 2.3.4 and I still have this exact same problem. When a non-author clicks on on the Submission link, they get this same messed up page. It is not bug #5547 as that patch has been incorporated into OCS 2.3.4.
I have figured this out, partly by searching the forum and finding this post:
http://pkp.sfu.ca/support/forum/viewtopic.php?f=3&t=7080So, even if a user doesn't have the Author role assigned to their profile, when they click on the Submission link, they are automatically assigned this role. I was ending up on the messed up page because the
Author registration opened date was set to a future date on the timeline management page and so the user could not be assigned the author role.