The info shown in the browser when octoprint server is not running shows outdated info for where to go for help now that this forum exists. example:
The OctoPrint server is currently not running If you just started up your Raspberry Pi, please wait a couple of seconds, then try to refresh this page. If the issue persists, please log into your Raspberry Pi via SSH and check the following: Verify that the process is running: ps -ef | grep -i octoprint | grep -i python should show a python process: pi@octopi:~ $ ps -ef | grep -i octoprint | grep -i python pi 1441 1 6 11:12 ? 00:00:15 /home/pi/oprint/bin/python /home/pi/oprint/bin/octoprint --host=127.0.0.1 --port=5000 If it isn't, the question is why. Take a look into ~/.octoprint/logs/octoprint.log, there might be an error logged in there that helps to determine what's wrong. You might also want to try if you can restart the server (if no obvious error is visible): sudo service octoprint restart. If all that doesn't help to trouble shoot the issue, you can seek support on the OctoPrint Mailinglist or in the OctoPrint G+ Community. Please provide your OctoPi and OctoPrint versions, your octoprint.log (in form of a pastebin link) and explain what you already tried and observed as detailed as possible.