I had node-red running for a couple of weeks on raspberry pi and had been working very well. I was modifying some sample nodes that I found online when the it became unresponsive. Its possible I did something that created some sort of infinite loop. I restarted raspberry pi and node-red... it seems to start normally but still no response via a web interface.
if you start it from the command line can you post the startup logs here please?
In case you don't know how to run it from the command line then, assuming you installed using the Pi install script from https://nodered.org/docs/hardware/raspberrypi then run
I ended up deleting the file flows_raspberrypi.json and it came back to life... I had copied it to another location first so I was able to import that back in and salvaged the good parts.