Hi Nirav ,
Did you replace Kernel at both Place in /sapmnt/<SID> and /usr/sap/<SID> ? just check the kernel version at both place . Did you get any issue during Kernel swich ( all executables copied properly ) ?
also as mentioned by Rishi you can reinstall Application server , SAP also suggest the same and it is easy to do .
THanks
Manas Behra