3571937 - Error "Could not load class com.sap.db.jdbc.Driver" in Determine DB Information Step using SUM tool.

An error occurs in the Determine DB Information Step while running SUM tool.

In the error log DMTINFO_XX_XX.ERR, it contains following entries.

Execution failed: Program has finished with error. Exit code: 1
Execution has been terminated. More information can be found in the log file <SUM path>/SUM/sdt/log/SUM/DMTINFO_XX.LOG.
Could not set up a database connection. See previous messages.
Could not establish open SQL connection. Exception com.sap.sql.log.OpenSQLException: Could not load class com.sap.db.jdbc.Driver with class loader System [class=sun.misc.Launcher$AppClassLoader,id=7480,parents=Extension@7429,urls=file:<SUM path>/SUM/sdt/,file:<SUM path>/SUM/sdt/lib/jperflib.jar,file:<SUM path>/SUM/sdt/lib/tools/iaik_jce.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~sec~csi.jar,file:<SUM path>/SUM/sdt/lib/_tc_exception_impl.jar,file:<SUM path>/SUM/sdt/lib/sdt_dmt.jar,file:<SUM path>/SUM/sdt/lib/tools/iaik_javax_crypto.jar,file:<SUM path>/SUM/sdt/lib/_tc_bl_opensql_implStandalone.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~bl~jkernel_dummy~frame_dummy.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~dd~db~dictionarydatabase~implDictionaryDatabase.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~bl~jkernel_util.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~antlr~antlr.jar,file:<SUM path>/SUM/sdt/lib/_tc_logging_java_impl.jar,file:<SUM path>/SUM/sdt/lib/730/sap.com~tc~bl~opensql~implStandalone.jar,file:<SUM path>/SUM/sdt/data/jdbc/ngdbc.jar,file:<SUM path>/SUM/sdt/lib/_tc_sec_secstorefs_java.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~logging~java~impl.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~bl~cache_api~impl.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~exception~impl.jar,file:<SUM path>/SUM/sdt/lib/tools/iaik_ssl.jar,file:<SUM path>/SUM/sdt/lib/sap.com~tc~sec~secstorefs~java~core.jar]..
com.sap.sql.log.OpenSQLException: Could not load class com.sap.db.jdbc.Driver with class loader System 

NetWeaver Java system.

SYS_INFO_EXPORT, Determine DB Information, Could not establish open SQL connection, Exception com.sap.sql.log.OpenSQLException, Could not load class com.sap.db.jdbc.Driver with class loader System , KBA , BC-UPG-TLS-TLJ , Upgrade tools for Java , Problem