Error in DB Tier Auto Config (java.lang.UnsatisfiedLinkError: libnjni11.so: libnjni11.so: wrong ELF class: ELFCLASS64)

After upgrading EBS database to 11GR2, we can encounter error while running autoconfig on the DB node 

Error:

java.lang.UnsatisfiedLinkError: /d11/oracle/TEST/db/tech_st/11.2.0/lib/libnjni11.so: /d11/oracle/TEST/db/11.2.0/lib/libnjni11.so: wrong ELF class: ELFCLASS64 (Possible cause: architecture word width mismatch)

Solution :

To fix this issue, Edit the database node xml as below and re-run the autoconfig.

 <JDK_TOP oa_var="s_jdktop">/d11/oracle/TEST/db/tech_st/11.2.0/appsutil/jre</JDK_TOP>

 <JRE_TOP oa_var="s_jretop">/d11/oracle/TEST/db/tech_st/11.2.0/appsutil/jre</JRE_TOP>

update to 

 <JDK_TOP oa_var="s_jdktop">/d11/oracle/TEST/db/tech_st/11.2.0/jdk/jre</JDK_TOP>

 <JRE_TOP oa_var="s_jretop">/d11/oracle/TEST/db/tech_st/11.2.0/jdk/jre</JRE_TOP>

Important Note:

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From 11gR2 DB version onwards AutoConfig on DB node uses the JRE from <Oracle_Home>/jdk/jre where as earlier versions of DB uses JRE from $ORACLE_HOME/appsutil/jre