calling JSP pages results in hanging 'blank' screen.
In Release 11i when performing the same steps new class files are created automatically when the JSP page is called from a browser session and JSP was rendered fine.
In Release 12 it's observed that when calling the JSP no class file is created in the directory $COMMON_TOP/_pages
The root-cause of the hang is the fact that the JSP is not 'translated' into the associated class file in the _pages directory. This is a mandatory step for processing the JSP page.
Solution to this is, use the ojspcompile.pl perl script to perform a manual pre-compilation of the JSP pages. The following command will compile all the JSP pages and build up the JSP cache again.
Linux: # $FND_TOP/patch/115/bin/perl ojspCompile.pl --compile --flush -p 2