Issue "server not running"

hello.
today, from nothing, appears this message.
tryed to restart, but nothing.
tryed to use putty and then "ps -ef | grep -i octoprint | grep -i python", but nothing happens.
tryed "sudo service octoprint restart", but nothing happens.
tryed to read the log but gaves me error.
tryed "sudo apt-get update&upgrade" but nothing.

i don't know how to fix it.
i would prefer to not reinstall it couse i have some plugins setted up correctly..

Do you mean it does not fix the issue or noting is happening at all?