Printer or scanner can not access a share for the can files after an upgrade.
Maybe some Windows Clients are not able to join anymore, too with the message wrong username or password.
With a new samba version we set the NTLMv2 version by default.
root@server:~# ucr set samba/ntlm/auth=yes
This fixes the issue in urgend cases. But I would strongly advise against setting it to “yes”. NTLMv1 is outdated since years and has so many security flaws.
If the printer is updateable and then able to “talk” NTLMv2 the solution to update the printer and use NTLMv2 is to be preferred.