(imported comment written by jessewk)
To avoid singular expression errors, use plural expressions. The following will ignore results from computers that don’t have the xml file, have malformed XML, or that don’t have nodes matching the specified xpath:
node values of attributes 0 of xpaths "//Hewlett-Packard
last()
/HPBatteryCheck
last()
" of xml documents of files “C:\Program Files\Hewlett-Packard\HPActive Support\Logs\battery.xml”