The error log is highlighting the problem
ORA-12154: TNS:could not resolve the connect identifier specified
Is Oracle installed on the same machine, if so you may need to update the tnsnames.ora
Have a look at the environment variable TNS_ADMIN, it might be pointing to <MIDDLEWARE_HOME>\user_projects\config\dbclient
If it is open tnsnames.ora and check it contains HFMTNS =....
Open the tnsnames.ora for the main oracle database e.g. <drive>\Oracle\product\11.2.0\dbhome_1\NETWORK\ADMIN\tnsnames.ora and copy the entries to the EPM tnsnames.ora
Sorry, but i did not get to follow you.
The Oracle DB Server is at another machine and on the server where the EPM 188.8.131.52 is, I've installed a Oracle client 64 bits.
Also at the client side has already an environment variable TNS_ADMIN point to C:\Oracle\OracleClient\product\11.2.0\client_1\network\admin
But at this same server I've found another TNSNAMES.ORA at folder :
and this file has the HFMTNS entry.
Are you meaning that the environment variable TNS_ADMIN should point to this folder ? (C:\Oracle\Middleware\user_projects\config\dbclient) and the entry HFMTNS from client should be at TNSNAMES.ORA on the server side ?
I've updated my TNSNAMES.ora from client and server and now it's working fine.