Spotlight on the Mac has stopped searching for programs and content in the docks. What to do?

Question

macOS

It does not find any programs installed, nor any content in the files.

Answer 1

This helped me:
* At the command line, enter the command: sudo mdutil -i on /
In fact, this is the same reindexing, but it is different because the standard reindexing method did not help me

Answer 2

In most cases, this helps https://support.apple.com/en-us/HT201716