This is a really odd combination of errors you’re reporting.
On one hand, getting a HTTP 403 Forbidden error is a foreign server error indicating that you’re requesting a download you’re not authorized to get. Of course, the profiles you’re downloading are all public URLs so 403 shouldn’t ever show up.
Can you share the file /var/log/mineos.log?
You’re running this from the command line? Because MineOS is just a front-end, so indeed we can do a lot of troubleshooting outside of the webui, in the terminal.
What is the actual output you get when you attempt to run the server manually with such a command?