Why are the email settings fields not showing, and how do I fix this? I'm trying to set up SMTP in Craft backend Settings > Email to get Mandrill working. But regardless of which protocol I choose, no settings fields are shown, and when I click save it just says "Couldn’t save email settings". It's the same in both Firefox and Chrome.

What could be the problem here, and how do I fix it?

Many thanks in advance and best regards.

/Monkey
Since I was short on time I ended up reinstalling Craft. Not exactly a minimum effort solution, but it fixed the backend > settings > email problem (and the updates page, that was not functioning properly as well). However, new install would not show my plugin in backend > settings > plugins. The solution to this, was to create a bare minimum test plugin (just copy pasted from https://craftcms.com/docs/plugins/setting-things-up), after which both the test plugin and my real plugin showed up in backend. All seem ok now.