Now it crashed again, but it is not responsive, it's on and display the error, but I can't connect to it with SSH or access the WebUI to get another diagnostics.
While this error is not one of the those I've have managed to screenshot, it is an error I've gotten before, it's "nf_nat_setup_info"
this happen after I started to stress-test my rTorrent docker, as I have suspected it's related to docker in some way. I started adding a few torrents, one after another and it very quickly crashed.
I tried to move things away from the SSD when I got this error message last time because I didn't want the SSD to be involved with the docker instances as I was afraid it had depleted sectors, so I moved the data to make sure that wasn't whats wrong.