When we repeat the phase in SUM tool when it stops in the phase PREP_INPUT/SELSTACKXML_ASK
SELSTACKXMLA.LOG
1 ETQ201 Entering upgrade-phase "SELSTACKXML_ASK" ("date and time")
2 ETQ373 parameter "EV_MESSAGE" = "XML file 'X:SUMabaptmp<STACK.xml>' does not exist or"
4 ETQ399 ... Error reading stack info (rc = 12, reason = "XML file 'X:SUMabaptmp<STACK.xml>' does not exist or")
4EETQ399 Stack configuration not useable: XML file 'X:SUMabaptmp<STACK.xml>' does not exist or
4 ETQ010 Date & Time: 20121212114317
1EETQ399 Last error code set is 'Stack configuration not useable: XML file 'X:SUMabaptmp<STACK.xml>' does not exist or'
1EETQ203 Upgrade phase "SELSTACKXML_ASK" aborted with errors ("date and time")
Related: Add on installation Stops in IMPORT_PROPER phase via SPAM or SAINT
You are getting above issue because the SUM is being run on a different server which is just connected to the system which is being upgraded.
Please do as following:
SAP recommends to run SUM in a local drive.
This is the main reason why the XML file wasn't copied to the tmp directory.
Kindly run the SUM tool locally in the system.