Sublime Text 3 does not save .html .css files - how to fix the problem? Reinstallation?

Question

css

Problem: Sublime Text 3 doesn't save .html .css files (I haven't tried the others), so Emmet doesn't work, which I really need.
At first I tried "Save as ..." in both Russian and English, and changing the encoding (instead of UTF-8 others). It didn't help at all - Sublime Text 3 saves without an extension and the system sees just a "file" if the names match, it asks if it needs to be replaced.
I'm just starting to learn HTML, I don't understand the subtleties right away. I installed it for a long time and painfully according to this instruction . All packages (or whatever it is called) were installed in C:\Users\User_name\AppData\Roaming. Everything worked, but today it doesn't. Help me please :)

Answer 1

What prevents you from specifying a file name with an extension?
video clip

Answer 2

just write like this index.html
and choose html extension