Hi, I am getting following error while compile with gcc(gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC)) /usr/bin/gcc -fpic -fpermissive -Wno-deprecated -Wcpp -D_POSIX_PTHREAD_SEMANTICS -fpic -fpermissive -Wno-deprecated -Wcpp -DPLATFORM_LINUX -DPLATFORM_LINUX_3_10_0_693_el7_x86_64 -D_RWCONFIG_m -D_LINUX -I/usr/opt/temip/tfc/include -I/usr/opt/temip/mmtoolkit/include -I/usr/opt/temip/acloc/include -I/usr/opt/temip/ocs/include -I/usr/opt/temip/tal/include -DPOSIX_4D9 -I. -I/sdboracle/orabase/product/10.2.0/rdbms/demo -I./../../../include -I./../../../include/cxx -I/Nuncas/oracle/app/oracle/oracle_ba/product/12.2.0/dbhome_1/rdbms/public -c Configuration.cxx Configuration.cxx ... In file included from ./../../../include/OInstance.hxx:43:0, from Configuration.cxx:37: ./../../../include/OInstanceList.hxx:53:40: error: âOInstanceâ was not declared in this scope class OInstanceList : public std::list<OInstance*>, public MTraceableObject { ^ ./../../../include/OInstanceList.hxx:53:50: error: template argument 1 is invalid class OInstanceList : public std::list<OInstance*>, public MTraceableObject { ^ ./../../../include/OInstanceList.hxx:53:50: error: template argument 2 is invalid Need your help for the resolution Regards, -Riaj