I set up the rails server with the same commands I always have, and now it doesn't work



For some reason I’m running into a problem with the rails server recently. Until recently putting in the same commands to run the server after I generated an app always worked the way it was supposed to. Recently I started getting this error even though I’m doing the same thing I’ve always done: I enter the following commands into the console:

either $ rails server -p $PORT -b IP or rails s -p $PORT -b $IP

When opening the page the application should be running on, instead of getting the Rails “you’re riding on Rails… screen” or application homepage respectively which is expected, I get the screen that says no application seems to be running here.
What am I doing wrong, and what can I do to fix it? thank you guys for all the technical support that you provide.