How do you mean it's not required? I get a big yellow error on the top of the MSSQL component telling me that jar is missing. Until it is loaded the component will error and the job will not build or run. If you have a magical way to tell Talend that this jar is not required please share it.
As far as errors, let me be clear, I am not making new jobs or changing old ones. We are talking about dozens of existing jobs that ran flawlessly and without complaint or error in 6.2. Now none of them run.