R12.0.4 patch 12792122, it fails with error "usdsop cannot create a new process

Hi,
When I try to apply patch 12792122, it fails with error

aiosp2() Error: failure in usdspn()

Contents of error buffer are:
"usdsop cannot create a new process

Cause: usdsop encountered an error creating a new process. [Reason].

Action: Check that your system had enough resources to start a new proce
act your system administrator to obtain more resou (RE"


An error occurred while extracting files from library.
Continue as if it were successful [No] :

You should check the file
C:\Oracle\apps\apps_st\appl\admin\OLM\log\u.12792122-new.log

for errors.