There should be an nzbdrone user, but it’s created in a way that it isn’t visible in the common places (I don’t fully understand what the deal is there), but it’s part of the sc-media group, so you can use that.
No, the user is nzbdrone which is in the sc-media group. Whether that will work for setting the ownership, I don’t know, you’d definitely need to give the group write access though.
Looks more like the version of Sonarr you’re running is older than the database it’s using, make sure Sonarr is up to date (the synology package is almost certainly out of date)/
Damn, that’s probably it. I’ve got a new Synology DS418 which uses the RTD 1296 chipset…no official support yet, so I grabbed a build WodKa78 compiled (https://github.com/SynoCommunity/spksrc/issues/2886), guessing my database was slightly more up to date than the version they compiled from.
Thanks for your help, sounds like I need to wait for official support…