I ran into a weird problem where I was unable to install PIA (PeopleSoft Internet Architecture) through the delivered install tools (PsMpPIAInstall or PSADMIN). It kept getting about 90% complete and then drop out and report an error saying PIA failed to install.
I was not able to find out much about the error, but what I did find was that I was missing a bunch of libraries specifically in my case WLST classes. As it turned out I had been cleaning up a bad install of another product and deleted the utils directory from the BEA home.
I re-installed the weblogic 10.3.0.4 version on the server into a new BEA home, and everything worked fine after that.
I found several cases that report multiple reasons for the failure but in the end the only thing that remained constant was re-install and everything works again. There are several directories that weblogic installs with that are necessary in order to make PIA install work.
Error: java.lang.RuntimeException: Could not find the OffLine WLST class
When doing the install you can issue the parameter: -debug -DDEBUG=true and that will issue thousands of information rows, but it does give some idea where the issue is.