What key shortcuts are to comment and uncomment code?

Question

There were Ctrl+E+C (comment) and Ctrl+E+U (uncomment) in older versions, or Ctrl+K+<

Answer 1

From your screenshot it appears you have ReSharper installed.

Depending on the key binding options you chose when you installed it, some of your standard shortcuts may now be redirected to ReSharper commands. It's worth checking, for example Ctrl+E, C is used by R# for the code cleanup dialog.