Upgrading to 19.0.1 - 403 Forbidden error

Manual upgrade following these directions: https://docs.nextcloud.com/server/latest/admin_manual/maintenance/manual_upgrade.html
Am receiving an error when I try to load the web interface that says:
You don’t have permission to access / on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.”

It looked like there were errors when I tried to do step 10 of the process (chown, find, setting permissions), which I assume is probably what’s causing the problems, but I don’t really know how to fix them. The errors said things like “operation not permitted” while trying to change permissions or ownership.
I have my installation at a cloud.mydomainname.com subdomain, so it’s possible I entered the commands incorrectly.

Any suggestions on what to try? Let me know if you need any more information to help with this.


What OS/version is it running on ?

The server is running Ubuntu 14.04.5 LTS. I’m not self-hosting this installation, it’s hosted on Dreamhost.