I'm using lyx-2.2.2 on Slackware-14.1 here. When I start a new presentation file I copy an existing one to the new directory with a new name. Have done this for years.
Today, just for giggles, I opened a new document and set the class to Beamer. But, when I look at the environments menu it's for a text class (book or article). I was really surprised by this. So, I followed past practice and copied a known-good .lyx file. Might I have done something incorrectly? Or is this just a fluke on my system? A curious mind wants to know, Rich