If you are viewing the web UI from a Windows Server machine (probably the same machine you installed on) the default security for IE11 will be higher, and you will need to add your IP to IE11 trusted sites to allow all components of webpage to display properly.

This issue is also a symptom of a bad install of FME Server.

In FME 2017.0 I've found that if you use the 'Custom\\Distributed' install option to install FME Server to allow
you to set a specific account to run the service with in the installer config for example. Then when installing you define a shared resource directory somewhere on the machine or your network where that user does not have permissions, you'll end up with a bad install (no warnings or errors).

Once installed, if you access the web interface you'll find
that you can't login with the admin credentials and the interface's login
button will be missing (not completely, just obscured). Further investigation for me revealed that the only services running were the web application service and the
database, the core hadn't started. Numerous reboots and some hacking later I
reinstalled, this time with the Express installer, again everything was fine till
I got to defining the network share and after issuing a UNC and clicking next
the installer complained that we didn't have permissions to this network share
path. Clearly that was the issue before but this time the installer checked and flagged up the issue. We granted the correct permissions and continued... When install was finished, everything
started and ran fine. Safe are aware (C128344), but thought it worth adding to this thread given that its a different type of permissions issue that caused the same problem.