The below error may occur if you are running the SQL-Toolkit plug-in on a Windows probe querying an MS SQL Server database.
ERROR: SQL-TOOLKIT Fail - [DBNETLIB][ConnectionOpen (SECDoClientHandshake()).]SSL Security error.(18)
This occurs when the DBA has disabled TLS 1.0 on the database server and enabled TLS 1.2.
The solution to this to is to check the existing SQL native client libraries are up to date and support SQL-Server side TLS versions. If TLS 1.2 is required then the below link may help in checking for updated version.