The SQL Server is not Available
This error comes up when launching Velocity and the Operators and/or Workstations have multiple entries with the same value.
To resolve this issue:
Open SQL Management Studio and connect to the instance containing Velocity
Expand Databases, Velocity, Tables
Open the dbo.Operators table
Check the Name column for duplicate operator names
Open the dbo.Workstations table
Check the WorkstationName column for duplicate operator names
If duplicates are found, change the names or contact the database admin