Oracle 10g AS R2 Webcache error - Permission denied when setting group ID

Objective: On startup of the Oracle 10g AS R2 middle tier, we got the following errors. Error --> Process (pid=9185) failed to start a managed process after the maximum retry limit Log: /u04/ora9i/ora10gAS/mtier/opmn/logs/WebCache~WebCache~1 And when we checked from the Enterprise Manager and opmn status command, it was showing that Portal and WebCache failed to start. CookBook: When we checked the event.log file under $ORACLE_HOME/webcache/logs directory it was showing the following messages. [02/Oct/2010:04:15:21 +0300] [notification 9612] [ecid: -] OracleAS Web Cache 10g (10.1.2), Build 10.1.2.0.2 050802 [02/Oct/2010:04:15:21 +0300] [notification 9403] [ecid: -] Maximum number of file/socket descriptors set to 900. [02/Oct/2010:04:15:21 +0300] [notification 13002] [ecid: -] Maximum allowed incoming connections are 700 [02/Oct/2010:04:15:21 +0300] [alert 9526] [ecid: -] Permission denied when setting group ID ( staff ). [02/Oct/2010:04:15:21 +0300] [alert 13003] [ecid: -] Configuration error. Stopping admin or cache server. [02/Oct/2010:04:15:21 +0300] [alert 9000] [ecid: -] Process 8259 exit(1) at 589:xmlcfglsnr.c [Build 10.1.2.0.2 050802] We found the error "Permission denied when setting group ID ( staff )". and on checking the logged in user, we found that user has the group other than "staff". we reset the group to staff, and restarted the application and every thing was fine.