The Problem: When you go to Events > Settings > Add-ons > Extended Views > there are no Style options visible.
The only settings option you see is “Show footer in Posterboard tile.”
The page is missing the following options:
Posterboard pages show at most
Stream pages show at most
Posterboard tile minimum width
Your hosting server's PHP may be outdated, or, it may need to be re-compiled with required extensions.
One user reported "iconv was not activated for PHP on my server" and enabling it fixed the problem.
A solution that worked for another user -- if you are using a multisite installation of WordPress, then disabling the calendar and the Extended Views plugin for each sub-site, then deleting the sub-site and re-creating it, then re-enabling the calendar and Extended Views was able to fix the problem.