I'm starting to give up, I reinstalled manually octoprint via console, did upgrade/update all packages, updated pip to the latest version and no go. Octoprint is not running. When I login via SSH it says OctoPrint version : unknown
Restarting the service does nothing. Also it stopped writing to octoprint.log for some reason, latest logs are before the upgrade I guess...
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.
I resolved this by rolling back to 1.3.10. Version 1.3.11 works fine on my Geeetech (OctoPi 0.15.0) but not my FLSun. The FLSun is running a MKS Gen 1.0 controller with Marlin 1.1.4. The Pi is a version 3 model B. OctoPi version is 0.14.0.