This message means that for some reason Sumac is unable to establish a connection to the database server computer.
Single-User Sumac (Trial, Bronze, Silver)
If you are running a single-user version of Sumac, the data is on your computer, so this message almost always means that another copy of Sumac is still running. Quit all running versions of Sumac and wait for half a minute, then run Sumac again. The problem normally goes away and you can run Sumac normally after that. If this does not fix the problem, restart your computer and try again.
Multi-User Sumac (Gold, Platinum, or Bronze and Silver combined with Sumac Cloud)
If you are running a multi-user version of Sumac, then Sumac connects to the database through a communication network. So there could be a problem with your network, with the database server, or with some other aspect of connecting to the server. The window in which Sumac tells you it cannot connect has a Test button; click the Test button.
In the test window, click the Check Server button. It tries to connect to the server whose name is to the left of the button. If it succeeds, it reports the IP address of the server. If it fails, then your server name is incorrect, or your network is broken and Sumac is unable to connect to the server; fix the network then restart Sumac and try again.
If the Check Server button was able to connect to the server, click the Connect button. Sumac attempts to connect to the MySQL server. If it works, it tells you so. If it fails, then confirm that MySQL is up and running on the specified server. You can ensure that MySQL is up and running by using the Services Manager on a Windows server, or the MySQL System Preferences on a Macintosh server.
If both Check Server and Connect worked, then the problem is with your database name or the database user ID and password: Sumac is attempting to connect to the database server and giving it a database name and the user ID and password for connecting to the database, but the server is rejecting them. You need to carefully check the database name, user ID, and password; these are displayed at the top of the Test window. If one of them is incorrect, you can click Edit to edit the databases.txt file (which is where Sumac gets information about database connections), save the changes to databases.txt, then quit Sumac and start again.
If you continue to experience problems, please contact the Sumac Support Team for assistance: support@sumac.com