kettle The PDI Client has encountered an error and may not be stable.

updating/cleaning the DB cache (right-click on your database-connection in PDI) might help.
I would suggest:
- clean the DB-cache
- recheck/configure your Table Output step
Then retry your transformation....

参考链接：https://forums.pentaho.com/threads/79188-Problem-with-quot-Table-Output-quot/

意思是刷新数据库缓存