Leaving this here for posterity, since I ran into the same issue, and this was the topmost search result.
For the record, I encountered this error running Docker on Windows.
While the Docker client was running the in the system tray, and was showing me as logged in, I got the
unauthorized: incorrect username or password error.
When I right-clicked on the system tray icon, it showed me as logged in, with a context menu item similar to
firstname.lastname@example.org: Sign out, the issue is that you must login to Docker using your hub username, which is different than your email address, even though in some cases, both are interchangeable.
You can do this by signing out from the system tray icon, or by logging in at a command prompt, using the syntax
docker login --username your_username_here.
If you’re not sure of your username, you can login to the Docker Hub, and your username will be displayed on the far right hand side of the menu bar, next to “Dashboard”, “Explore” and such.