Spotfire Node manager services: Services fail to start with "Class path contains multiple SLF4J providers" errors in logs

When trying to start a service on the node manager and you get errors similar to the below in the service-[GUID]-stdout.log:

Starting python-service...
Error: SLF4J(W): Class path contains multiple SLF4J providers.
Error: SLF4J(W): Found provider [org.slf4j.nop.NOPServiceProvider@50468873]
Error: SLF4J(W): Found provider [org.apache.logging.slf4j.SLF4JServiceProvider@146587a2]
Error: SLF4J(W): See https://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Error: SLF4J(I): Actual provider is of type [org.slf4j.nop.NOPServiceProvider@50468873]

This is usually due to the service port being blocked by a firewall or similar network block

To resolve make sure to open the ports in use by the services (port 9501,9502... are the default ports used)