After installing R1211 with rapidwiz, I tried to run admrgpch to merge the R1211 preinstall=y patches listed in an earlier post. I received an error: admrgpch: fatal: libclntsh.so.10.1: wrong ELF class: ELFCLASS64. I found a related note on MOS, R12 – adcfgclone appsTier fails with error for ld.so.1 ‘wrong ELF class: ELFCLASS64’ [ID 1078123.1]. However, this did not fix the problem, but gave me a clue to what was wrong. It turns out the issue was the oraInventory for the Apps tier was not write-able by the applmgr user. I copied the old central oraInventory to oraInventoryback and then I made sure the oraInst.loc had the inst_group=dba. I changed the location of the oraInventory in all the Apps tier oraInst.loc locations to a write-able directory and reinstalled the Apps tier with rapidwiz. This solved the problem.