Credit for the following information goes to a commenter on this blog named Deezel. And also, of course, to Oracle for figuring out the fix!
In the Hyperion / Oracle EPM 11.2.x series of releases, Critical Patch Updates are available to fix significant security vulnerabilities in Oracle WebLogic Server 12c and Java 8.
Unfortunately, one of the WebLogic patches require an update to the OPatch utility, and the update cannot be rolled back successfully. So if you're on EPM 22.214.171.124 through 126.96.36.199, you cannot redeploy your web applications after performing the in-place upgrade to 188.8.131.52. You get a generic error in configTool and the back-end log error messages are unhelpful.
What follows are Oracle's instructions on how to work around the issue. Again, a big thank you to commenter Deezel and I look forward to applying the fix in one of my bricked sandboxes.
I cannot emphasize enough the importance of following Oracle's advice by backing up the folders. Best of luck!
After Update from 11.2.4/11.2.3 to 11.2.5 deployment of products fail.
The steps listed here are to restore the Updated 11.2.5 instance with deployment failures to working state.
Take back up of EPMSystem11R1 and user_projects folder available under Middleware Home.
1 Stop all services
2 Delete all the folders under MWH except EPMSystem11R1, dbclient32,dbclient64 and user_projects
3 Rename the .oracle.products available at EOH\.oracle.product as .oracle.products_11.2.5
4 Rename the .oracle.products0 as .oracle.products
5 Run Apply Update
6 Configure as per Update Guide
7 Start Services
8 Sanity test passes