Notepad++: block comment not working

I am running Notepad++ 5.8.5 on Windows 7, editing Perl programs. I would like to comment out a block of text lines (and later, perhaps, uncomment it).
None of the following works: CTRL+K, CTRL+Q, CTRL+shift+K, CTRL+shift+Q,
selecting the block of lines and going to the menu: edit-> Comment/Uncomment -> Block Comment

none of the above has any effect.
What to do?

How do you comment multiple lines in notepad?

Comment Out Multiple Lines in Notepad++ Select the lines you want to comment out and press Ctrl + Shift + Q or click Edit > Comment/Uncomment > Block Comment. That's all. You can uncomment lines by selecting them, and after that, click Edit > Comment/Uncomment > Block Uncomment.

How do you insert a block comment?

To make a block comment: On a PC: Ctrl + Shift + / On a Mac: Command + Opt + /

Is NP++ interpreting your file as Perl or plain text?

If NP++ is treating your file as plain text, then language specific things like that won't work.

You may want to double-check that as described here.