Usually, you should look at the code (click the tab at the bottom-left of your design area) and find the exact line on which the NPE occurred to identify the problem.
(See the first number in the stacktrace e.g. 516 in the following:
Exception in component tJava_1
java.lang.NullPointerException
at idm_from_superb.test_0_1.test.tJava_1Process(test.java:516)
at idm_from_superb.test_0_1.test.runJobInTOS(test.java:842)
at idm_from_superb.test_0_1.test.main(test.java:601)
)
However, in this case, I don't see a tMysqlConnection so where will tMysqlLastInsertId get its value from? It needs to share a connection with tMysqlOutput to work. Did you read the component help to understand how to use it?