Attempting to mount a client to an SMB network share and you can receive the message:
When connecting to a network share and the share name is incorrect, you will receive a very confusing error message.
net use x: \\Server\XYZ System error 1240 has occurred. The account is not authorized to log in from this station.
Selecting the correct share name (XYZ1 instead of XYZ) resolves this.
net use x: \\Server\XYZ1 The command completed successfully.
The error message caused by selecting a non-existing share makes this error message confusing.