2382789 - Application server fail to start after Kernel update / Upgrade / Installation

After a Kernel update / upgrade / installation procedure, one or more servers fail to start.

The most common situation for which this document applies is where there is one instance running normally and this instance is the ASCS or the Central Instance (The one in which message server is running) and one or more servers are presenting errors to initialize and work correctly.

Upon checking the message server trace file (/usr/sap/<SID>/<instance>/work/dev_ms) the following entries are seen over and over:

1. [Thr <nr>] MsSSetRelInfo: client ip.addr.from.client not compatible system/client (release: 7XX / 7YY, complvl: 0/0)
   

   Where:

   7XX is the current Kernel release of the message server

   7YY is the current Kernel release of the client trying to connect, in this case the application server with IP ip.addr.from.client

         Upon checking the dispatcher trace file (/usr/sap/<SID>/<instance>/work/dev_disp) from the affected application server, the following entries can be seen:

         *** ERROR => MsISnd2: not_attached [msxxi.c 1818]
         ***LOG Q0N=> DpSendToMs, MsSndName () [dpMessageSer 3706] 
         ....

        ***LOG Q1K=> MsIAttachEx: compatibility check failed, Kernel not compatible with system [msxxi.c 1031]
   
        And / Or

        DpUpdateStatusFileWith: state=YELLOW, reason=Server in state STARTING

2. [Thr <nr>] MsSSetRelInfo: client ip.addr.from.client not compatible system/client (release: 7XX / 7XX complvl: 0/1)
   

   Where the same Kernel release appears in the message server (dev_ms) and in dialog instance trying to connect and the error appears when trying to install a Hot fix in the dialog instance.
   
   The messages in the dispatcher trace file (dev_disp) are the same as in 1)

• Operating System independent
• Database independent
• SAP NetWeaver
• SAP Web Application Server for SAP S/4HANA
• ABAP Platform 

kernel update, not compatible , KBA , BC-CST-STS , Startup Service , BC-CST , Client/Server Technology , Problem