Problems moving to new Mac

I've tried to follow the directions, but I am having nothing but trouble - Upgrading my old Mac mini to a new M1, moved my old usb drive over to the new machine, and everything works fine with it - except Channels.

When I try to show it the directory, it gives me a permissions error "mkdir can't write" - I have no problem writing to the drive from any other app, or reading and writing at finder level, and I have checked the permissions and its set to r&w for everyone, so I am at a complete loss.

Now, I put the old mini back and did a “restore”, and it basically seems to now be working - but the difficulty in transferring the setup to a new machine is extremely frustrating -

Any help or ideas greatly appreciated -

It's probably under Settings.app > Privacy, there are new removable disk permissions you have to grant per app. It should prompt you the first time you setup the dvr, but maybe that got dismissed.

That seems to have done it -

A section on specific issues with different platforms would be really helpful - I am also trying to get it installed on this new mini in a non-administrative user account, as I am also using it to monitor multiple security cameras, and a file server, plus potentially others -