The OH/lib/facilities.lis file is useful. It tells you a specific "facility" is part of what "component" of Oracle software. Thanks Jared. I just ran dir/s to find all *.msg files: D:\app\oracle\product\12.1.0\db>dir /s *msg Volume in drive D is DATA Volume Serial Number is 4AD1-F106 Directory of D:\app\oracle\product\12.1.0\db\crs\mesg 04/16/2013 09:37 PM 548,245 crsus.msg 1 File(s) 548,245 bytes Directory of D:\app\oracle\product\12.1.0\db\css\mesg 08/12/2003 07:21 PM 8,293 clssus.msg 1 File(s) 8,293 bytes Directory of D:\app\oracle\product\12.1.0\db\has\mesg 08/26/2008 07:20 PM 24,414 clsdus.msg 11/08/2012 10:25 PM 64,018 clsgnus.msg... and ran oerr on a random "facility" successfully, e.g. D:\app\oracle\product\12.1.0\db>oerr clsd 1 0001, 0, "Error flushing trace data for component %s" // *Cause: One of the lower layers have failed to write the data out. // *Action: None This obviously comes from clsdus.msg, installed with the software (i.e. I didn't copy it from my Linux box). Yong From: Jared Still <jkstill@xxxxxxxxx> To: Yong Huang <yong321@xxxxxxxxx> Cc: "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx> Sent: Monday, November 3, 2014 9:31 AM Subject: Oracle 12c on Windows - oerr files Thanks Yong. That's the way it has been on windows for a long time. Kind of silly that a customer shoul be forced to jump through hoops to get this basic functionality. The location of all msg files can be found in OH/lib/facilities.lis as I recall. Jared On Monday, November 3, 2014, Yong Huang <yong321@xxxxxxxxx> wrote: Jared, I blogged about this 12c oerr.bat: "To use it, you need to set s_oraclehome to the same as %oracle_home%, set perl5lib to %s_oraclehome%\perl and copy at least oraus.msg from any Linux/UNIX Oracle box, which is missing in %oracle_home%\rdbms\mesg" (from http://yong321.freeshell.org/freeware/Windowsoerr.html) You have to have *.msg files copied from somewhere else, at least for Oracle 12.1.0.1. (I didn't install 12.1.0.2 to check it.) Yong Huang -- Jared Still Certifiable Oracle DBA and Part Time Perl EvangelistPrincipal Consultant at Pythian Pythian Blog http://www.pythian.com/blog/author/still/ Oracle Blog: http://jkstill.blogspot.com Home Page: http://jaredstill.com