2315992 - Error during phase PREP_INPUT/INSTANCELIST_PRE "OS user password does not work, please reenter"

• An error occurs during an upgrade using the Software Update Manager (SUM) during phase PREP_INPUT/INSTANCELIST_PRE
•  The error message is: "OS user password does not work, please reenter"
• In INSTANCELIST_PRE.LOG you see the error similar to:
  
  

  1 ETQ359 RFC Login to: System="<SID>", AsHost="<hostname>" Nr="<instance>", GwHost="<GW Hostname> ", GwService="sapgw<##>"
  2EETQ231 RFC Login failed
  1EETQ399 SYSTEM MANAGER: Initialize instance list has failed.
  1EETQ399 SYSTEM MANAGER: Error during RFC call (put_rfcupg_read_sys_environment) with params '<hostname>', '<SID>', '<Instance>'
  1EETQ399 Last error code set is: RFC login to system <SID> ashost <hostname> nr <Instance> gwhost <GW Hostname> gwservice sapgw<##> failed with code 1 key RFC_COMMUNICATION_FAILURE: 
  LOCATION CPIC (TCP/IP) on local host with Unicode
  ERROR partner '<hostname>:<port>' not reached
  TIME Mon May 09 12:16:07 2016
  RELEASE 721
  COMPONENT NI (network interface)
  VERSION 40
  RC -10
  MODULE nixxi.cpp
  LINE 3283
  DETAIL NiPConnect2: <IP Address>:<port>
  SYSTEM CALL connect
  ERRNO 10061
  ERRNO TEXT WSAECONNREFUSED: Connection refused
  COUNTER 26

  1EETQ204 Upgrade phase "INSTANCELIST_PRE" aborted with severe errors ("2016xxxxxxxxx")

KBA , BC-UPG-PRP , Upgrade Preparation , Problem