So everytime I login to usermin at mysite.com:20000 and access my email, virtualmin at mysite.com:10000 goes to a 404 and I have to reboot my server and then it’s back up no problem.
CentOS 7.7 
Thanks for the pointers! If there’s any other server info I can provide please let me know. Ty!
Hi,
Thanks for the feedback.
Can you reproduce it steadily? It sounds like a fun “bug”. Okay, if you try it again, after logging in to Usermin, do you still have Webmin going down? If so, what is the output of the following command:
systemctl status webmin
Besides, what Webmin, Usermin and Virtualmin versions are you running there?
Almost certainly the OOM killer. Check memory usage. You may need to add swap or increase available RAM.
Usermin and Webmin are wholly separate services, completely independent of each other, and Usermin can’t alter Webmin (Usermin drops privileges, so it has no capability to do anything to Webmin). There’s no way logging into Usermin can break Webmin (Webmin could affect Usermin, but only if you do something in Webmin that changes the configuration of Usermin).