Problem:
You want to run ng upgrade
to update your angular project libraries, but you see this error message:
The specified command ("upgrade") is invalid. For a list of available options, run "ng help". Did you mean "update"?
Solution:
You need to run
ng update
instead of ng upgrade
(which is not a valid command).
This is what Did you mean "update"?
in the error message is intended to point you towards.