The database is run from a program called the "Connection Manager". If it is not running, you will not be able to access the database. From the Start Menu, select the Sage 50 program group and look for the Connection Manager. Open it and see if it is running. If the button near the bottom says Start Service then you need to hit it to start the Connection Manager.

If it is already running and running as a service (see the top left-hand corner under Status), then likely something has changed in your firewall or you just need to reboot your computer.

Thanks Richard
Connection Manager is running. I recently installed Norton security. I made sure that the Sage is part of the Firewall. Just in case I need to double check what are the required programs that the firewall needs to authorize for Sage 50?

Thanks

Likely it is Norton. You might want to check the Knowledgebase for an article on it's specific settings.

but otherwise start with:

C:\Program Files\winsim\ConnectionManager\SimplyConnectionManager.exe
C:\Program Files\winsim\ConnectionManager\MySqlBinary\5.6.10\MySQL\mysqld.exe
C:\Sage502015\Sage50Accounting.exe

Note1: if you are on a 64-bit computer, you want Program Files (x86).
Note2: your program installation may be to Program Files... so replace the c:\Sage502015 with c:\Program Files... or other proper path to your Sage 50 program.

The above three should get you through but if they don't get it working, then try the following, one at a time.

C:\Program Files\winsim\ConnectionManager\Simply.SystemTrayIcon.exe
C:\Program Files\winsim\ConnectionManager\MySqlBinary\5.6.10\MySQL\mysqladmin.exe

And if you need more, there is an article in the Knowledgebase that lists a ridiculous number of programs.