I have been a unix user since the early '80s and an Ubuntu user since some time in the '00s and I have never been stumped by a problem the way this has stumped me.
I recently did clean (erase the disk and start over) installs on 4 PCs. They are all currently running 24.04.1. There has been some fiddling around while trying to solve this problem.
For the first time in all that time I "need" to use personal file sharing. I now have my first CNC machine and want to be able to send files to it from my desktop and laptops.
Ubuntu has advertised personal file sharing for a very long time. There is a "public" directory tagged with sharing icon indicating that it can be used to share files. In fact I have used it do get and put files to MS Windows machines. So, at some level it has worked in the past.
Ok, so I go to settings/sharing and there is no control to enable file sharing. Media sharing is there. And, I have made that work in the past. But file sharing is not where I saw it on older versions of Ubuntu.
Searching the web I find I have to install gnome-user-share to enable file sharing. I did that using synaptic on all 4 machines. Sure enough the file sharing option showed up in setting/sharing. I used it to share my public directories on 3 of the machines. The directories showed up on all the machines.
But, when I tried to open the files I get a message saying

The problem is that I do not have a domain named ".local" that I know off. Nslookup of the same name says
nslookup cnc
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: cnc.attlocal.net
Address: 192.168.1.195
Name: cnc.attlocal.net
Address: fe80::cfdc:825:abcf:e7e
Name: cnc.attlocal.net
Address: 2600:1700:211:ee40::20
Name: cnc.attlocal.net
Address: 2600:1700:211:ee40:69c4:fcc:58b3:1273
Name: cnc.attlocal.net
Address: 2600:1700:211:ee40:ec89:aa9e:ebf9:fad3
ping says
ping cnc
PING cnc (2600:1700:211:ee40::20) 56 data bytes
64 bytes from cnc.attlocal.net (2600:1700:211:ee40::20): icmp_seq=1 ttl=64 time=95.1 ms
64 bytes from cnc.attlocal.net (2600:1700:211:ee40::20): icmp_seq=2 ttl=64 time=317 ms
64 bytes from cnc.attlocal.net (2600:1700:211:ee40::20): icmp_seq=3 ttl=64 time=239 ms
64 bytes from cnc.attlocal.net (2600:1700:211:ee40::20): icmp_seq=4 ttl=64 time=62.7 ms
host says
host cnc
cnc.attlocal.net has address 192.168.1.195
cnc.attlocal.net has IPv6 address 2600:1700:211:ee40::20
cnc.attlocal.net has IPv6 address fe80::cfdc:825:abcf:e7e
cnc.attlocal.net has IPv6 address 2600:1700:211:ee40:bc31:8c1f:1e3b:275c
So, no ".local" anywhere I can find.
OK, since gnome-user-share is not installed by default and file sharing has been part of Ubuntu for a long time, I have to assume there is a problem with the current version of file sharing.
Anyone one know if this is being worked on? (I already admitted it is beyond me.) Anyone know what the problem is? Any idea when this will be fixed?