After running the snap refresh command, an error is shown when looking at the status of network manager. Here is what it looks like:
The output can be viewed with snap changes command:
The text is:
6 Error today at 01:39 UTC today at 01:42 UTC Auto-refresh snap "network-manager"
Why would it error out?
What does snap change 6 say ? Just looking at the top level list of messages will indeed not tell you a lot 
@ogra yes, so it does tell me the details. Here they are:
user1-company@ubuntu:~$ snap changes
ID Status Spawn Ready Summary
1 Done today at 01:06 UTC today at 01:09 UTC Initialize system state
2 Done today at 01:09 UTC today at 01:10 UTC Initialize device
3 Done today at 01:14 UTC today at 01:15 UTC Install "usbutils-lool" snap
4 Done today at 01:16 UTC today at 01:16 UTC Install "pciutils" snap
5 Done today at 01:38 UTC today at 01:58 UTC Refresh snaps "bluez", "core20", "intel-kernel", "lenovo-wwan-dpr", "modem-manager", "pc", "quectel-firmware-switch", "snapd"
6 Error today at 01:39 UTC today at 01:42 UTC Auto-refresh snap "network-manager"
7 Done today at 02:15 UTC today at 02:16 UTC Refresh "network-manager" snap
user1-company@ubuntu:~$ snap change 6
Status Spawn Ready Summary
Done today at 01:39 UTC today at 01:42 UTC Ensure prerequisites for "network-manager" are available
Undone today at 01:39 UTC today at 01:42 UTC Download snap "network-manager" (829) from channel "20/stable"
Done today at 01:39 UTC today at 01:42 UTC Fetch and check assertions for snap "network-manager" (829)
Undone today at 01:39 UTC today at 01:42 UTC Mount snap "network-manager" (829)
Undone today at 01:39 UTC today at 01:42 UTC Run pre-refresh hook of "network-manager" snap if present
Undone today at 01:39 UTC today at 01:42 UTC Stop snap "network-manager" services
Undone today at 01:39 UTC today at 01:42 UTC Remove aliases for snap "network-manager"
Undone today at 01:39 UTC today at 01:42 UTC Make current revision for snap "network-manager" unavailable
Undone today at 01:39 UTC today at 01:42 UTC Copy snap "network-manager" data
Undone today at 01:39 UTC today at 01:42 UTC Setup snap "network-manager" (829) security profiles
Undone today at 01:39 UTC today at 01:42 UTC Make snap "network-manager" (829) available to the system
Undone today at 01:39 UTC today at 01:42 UTC Automatically connect eligible plugs and slots of snap "network-manager"
Undone today at 01:39 UTC today at 01:42 UTC Set automatic aliases for snap "network-manager"
Undone today at 01:39 UTC today at 01:42 UTC Setup snap "network-manager" aliases
Error today at 01:39 UTC today at 01:42 UTC Run post-refresh hook of "network-manager" snap if present
Hold today at 01:39 UTC today at 01:42 UTC Start snap "network-manager" (829) services
Hold today at 01:39 UTC today at 01:42 UTC Clean up "network-manager" (829) install
Hold today at 01:39 UTC today at 01:42 UTC Run configure hook of "network-manager" snap if present
Hold today at 01:39 UTC today at 01:42 UTC Run health check of "network-manager" snap
Done today at 01:39 UTC today at 01:42 UTC Handling re-refresh of "network-manager" as needed
......................................................................
Run post-refresh hook of "network-manager" snap if present
2023-05-24T01:42:09Z ERROR run hook "post-refresh":
-----
ERROR: 1.16.6 version of ModemManager detected, while 1.18 or newer needed.
Please install a newer version of ModemManager and retry.
-----
user1-company@ubuntu:~$
I am assuming this “post-refresh” hook is a shell script that needs to be run manually. Where is it? Do I just SSH into Ubuntu Core and run it? Is this the way it is supposed to work?
no, hooks are run by snapd automatically, nothing manual is needed and the error message is pretty clear, isn’t it ?
network manager can only work with certain versions of modem manager …