Tools
Crash dump reader
Paste a crash dump from your server's crashdumps folder and see what broke, which plugin is behind it and what usually fixes it.
From your server
Servers and tools can send a crash dump themselves and get the link back:
curl -H "Content-Type: text/plain" --data-binary @crashdumps/your-crash.log https://crash.vanillamine.com/api/v1/crashdumps