No connection to the database when using ODBC

[AtanasM]

In an Access application with 5 users, an ODBC is set up locally as a System DSN for each user. Since yesterday, one of the users got the message "No connection to the database". All other users could continue working normally.
The existing ODBC could no longer be edited, not even as an administrator.
I created a new DSN user already, but it doesn't work.

[#2]

@AtanasM 

• Does this user have the same rights as other users?
• Are you using Windows Authentication or SQL Server Authentication?
• Is the location of the server accessible to this user via the network? 
• Can you log on to the server from this user's computer using your own login?

This kind of information can help find the problem....

[#3]

@George Hepworth
Please check below the answers:
Does the affected user have the same rights as other users? Yes
Are you using Windows Authentication or SQL Server Authentication? Windows authentication
Is the location of the server accessible to this user over the network? Yes
Can you log into the server from this user's computer with your own login? No

[#4]

@AtanasM 
"Can you log into the server from this user's computer with your own login? No" [emphasis added]

That suggests the problem is NOT the DSN. That suggests the problem is with the connection between that computer and the server. I should have asked also, if this user can log in using their credentials from a different computer (that would help confirm the diagnosis).

It could be a firewall problem on that computer, for example. If recent updates to the Windows OS were made, that could also be implicated. I think you need to focus, not on the DSN itself, but on the connectivity between that one computer and the database on the server.