Rails doesn't find nokogiri. What is the problem?

Question

Ruby on Rails

I am writing in the rails server console.
An error:

Could not find nokogiri-1.10.10 in any of the sources

Run `bundle install` to install missing gems.

I enter the bundle install command, I try to start the server again.
The same error appears again.

Answer 1

Solved a problem.
I tried to install nokogiri again, it was written that it was already installed.
Once again I entered bundle install
Now everything works
But why it happened, it's not clear