Please ensure that your database is online and running and that the connection string in your web.config file is correct.
1. Open [Install Location of Community Server]\web\web.config
2. Within web.config find the configuration section (highlighted) below:
<configuration> <appSettings> <add key="SiteSqlServer" value="[Your connection string here]" > </appSettings> </configuration>
3. Modify the value to properly identify your database.
For example, to connect to a database named ‘CommunityServer’ on the current machine with an account ‘csSystem’ and the password ‘pa$$word12’:
connectionString = "server=.;database=CommunityServer;uid=csSystem;pwd=pa$$word12"
For more information you can also visit http://www.communityserver.org the home of Community Server.