Thanks It worked
If it helps others, I’ll give a little extra : I had to stop the app because the server couldn’t allocate the memory. So I run these commands :
cd /var/discourse ./launcher stop app
I run the command @pfaffman gave me, did a new swap, started the app and rebooted my server
cd /var/discourse ./launcher start app
Then for the reboot :
shutdown -r now (I don’t know if it was neccessary, but it never hurts)
Thanks again !