The ArcGIS Publishing Service has an error showing: The server is not ready for publishing.

Error Description:
Error:the server is isn't ready for publishing. Please check if the Publishing Tools on the server are started.
Cause of the error: In this case the main reason is that you did not open your ArcGIS Server Manager service.

Please go to your http://localhost:6080/arcgis/manager/index.html URL to start the service.

ArcGIS Server Manager
Open ArcGIS Server Manager, and then log on.
Click Service > Management Services. The Management Services module appears and the Start and stop buttons appear. If the Stop button is dimmed, it means that the service is currently stopped. Conversely, if the startup button is dimmed, this means that the service is started and is currently running. Click one of the commands. This command applies only to the service selected in the module.

As shown above the state, is a stagnant state. Click the Start button to start the service.
In addition, if you click Start or stop continuously, you will get an error:
Error while starting appserver. Required Port ' 4000 ' already in use.
In this state it is generally stated that your service has been started and no more service is required.

The Stop button above is grayed out and the service is in a stopped state.
When the startup button is grayed out, the release process is slow, please be patient.