Failed to connect to database. The geodatabase is not accepting connections. Please contact your geodatabase administrator

Error Message

In ArcGIS for Desktop, when attempting to establish a connection to a geodatabase, the following error is returned:

Error:   
Failed to connect to database. The geodatabase is not accepting connections. Please contact your geodatabase administrator.

Cause

The 'Geodatabase is accepting connections' check box is unchecked in the database properties, which prevents new connections to be made to the geodatabase.

Solution or Workaround

Enable the Geodatabase is accepting connections option.

Note: 
Only a geodatabase administrator can apply the steps provided below.

1. In ArcMap, navigate to the Catalog pane.
2. Right-click the target database > Properties > Connections tab.
3. Check the Geodatabase is accepting connections check box.
4. Click Apply to confirm the new database connection settings.