The above example exception notes AS400JDBCConnection, however this could occur with any supported data source, such as:
MySQL: java.lang.AbstractMethodError: com.mysql.jdbc.Connection.isValid(I)Z
The JDBC driver is outdated and as such it implemented Java 1.6's Connection#isValid()
method.
Reference the supported data source documentation.
If the driver is not provided with Test Data Manager (TDM), then upgrade the JDBC driver accordingly and/or contact the vendor of the JDBC driver if there are any questions about the implementation of specific methods, such as isValid().
While a highly unlikely scenario, if the driver is provided with TDM, please open a case with Support, so we can assist you accordingly.