1. Make sure all Stat users are logged off.
2. Shutdown Stat Central Agent. Go to Tools | Stat Central Agent Status to make sure it is not responding.
3. Login to Stat database through a tool such as SQLPlus with DB user id of STAT.
4. Run the following statements to Alter tables - merc_csr_event & merc_misc_event for column - PREV_TRACKING_NUMBER to VARCHAR2 (60)
ALTER TABLE STAT.MERC_CSR_EVENT MODIFY (PREV_TRACKING_NUMBER VARCHAR2(60));
PROMPT * Alter Table MERC_CSR_EVENT
ALTER TABLE STAT.MERC_MISC_EVENT MODIFY (PREV_TRACKING_NUMBER VARCHAR2(60));
PROMPT * Alter Table MERC_MISC_EVENT
5. On Stat agent machine go to %STAT_HOME\app\server\default and delete data,tmp and work folders. These are tmp files and folders that get recreated when you restart the agent.
6. Restart Stat Central Agent. Go to Tools | Stat Central Agent Status to make sure it is responding.