My Ubuntu 20.04 does not access the windows network (D-link NAS-320L Share center), the error is the following: Failed to mount the windows share: Connection termination caused by software.In previous distros everything was normal.
I found this solution on internet.. By Tejas Lotlikar: Same issue here.
Since version 4, both Samba Server & Samba Clients do not allow an older level of protocols negotiation. You have to enable them in smb.conf file
Edit /etc/samba/smb.conf file (need root permissions)
in the [global] section, add the following line
client min protocol = NT1 Save the file and exit the editor.
You must restart the Samba Service for this change to take effect. In a terminal, enter this command:
sudo service smbd restart