How to fix 'Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.'

Question

I have the following error in the Chrome Dev Tools console on every page-load of my Node/Express/React application:

Unchecked runtime.lastError: Could not es

Answer 1

I get the message only on the first Chrome page =
When Chrome is not running, and I open it - either directly or by double-clicking on a page on my desktop.
(I don't know if this matters, but I have "Continue running background apps when Google Chrome is closed" off.)
So, I'm assuming it's Chrome's crap spying/"enhancing user experience" attempt.
I don't know what it's trying to send, but I'm glad it's not able to! :)
So, second (or any but first) tab has no error.
== No need to disable anything (extensions, etc.).