If you set the database(s) to use Server instead of ODBC, the system wants to create a System 32bit ODBC entry.  If you launch for the first time with non-administrative / power user permissions, the ODBC entry will likely not be created.
Try the following:
1. Set databases to Server (SQL connection)
2. From the client, launch Database Setup - AS ADMINISTRATOR
3. Click the Verify icon
4. Select a database to verify

If the above fails, there is an issue with the PC and workstation setup should be run again (as administrator).  If it connects and scans tables, the system will have created a 32bit server-level ODBC connection in the system section of the ODBC admin snap in and you should be good.

Hello Gentlemen,

All the usual mentioned as possible culprits in this thread turns out okay. That is, they have been setup accordingly. I am running Sage 300 2023 on Windows 11. What I picked up during the WSSETUP is that Sage 300 installs "ODBC Driver 18 for SQL Server" and by default an ODBC DSN is setup to use this driver even though it still fails to connect. When I remove this data source and to setup a new data source using "SQL Server Native Client 11.0", it still fails to connect. The client is running MSSQL Server 2019 EXPRESS.

I don't really like SQLEXPRESS because of its default settings, but I don't have a choice here. Is there anything else that I could be missing?

Hello Gentlemen,

All the usual mentioned as possible culprits in this thread turns out okay. That is, they have been setup accordingly. I am running Sage 300 2023 on Windows 11. What I picked up during the WSSETUP is that Sage 300 installs "ODBC Driver 18 for SQL Server" and by default an ODBC DSN is setup to use this driver even though it still fails to connect. When I remove this data source and to setup a new data source using "SQL Server Native Client 11.0", it still fails to connect. The client is running MSSQL Server 2019 EXPRESS.

I don't really like SQLEXPRESS because of its default settings, but I don't have a choice here. Is there anything else that I could be missing?

Go through the ODBC configuration settings for the client.  There is one screen that has a check box field to trust the server.  If you put a check mark in that field, it will work

Hello Abenaki,

My apologies. I had incidentally posted a question to this effect in another thread without realizing that you have responded already under this thread. I will not mind if the moderator deletes the other thread and leaves this one.

I will test this solution in the new year (next week) when the Client is back at work.

Thee are a bunch of settings that need to be turned on if using SQL Express:

Enable remote connections

Configure SQL to listen on static port

Turn on SQL browser service

Configure Firewall

Hello Abeneki,

I was able to establish connection by following your advice and once I checked the "Trust server certificate" option everything worked out fine.

Thank you, Darren. I am aware of all these settings with regard to SQLEXPRESS.