Refer the first Knowledge base article as below noted,
Creating OCE File In Interactive Reporting Studio Returns Error: "Oracle Error - 1: ORA-12154: TNS: Could Not Resolve The Connect Identifier Specified" (Doc ID 1576580.1)
Else check the below steps
This is noted in another knowledge base article
Hyperion BQY OCE Connection Error: "Ora-12154: TNS:could not resolve the connect identifier specified" (Doc ID 1072291.1)
User cannot connect to the Oracle database data source with a newly published OCE file on the workspace.
Getting the following error when connecting:
"Ora-12154: TNS:could not resolve the connect identifier specified".
The DSN is failing to read the tnsnames.ora file.
Where the tnsnames.ora file is mapped to a different location from the default one, the Hyperion servers are unable to read it.
Returning the tnsnames.ora file to the customary location (\oracle\product\10.2.0\db_1\NETWORK\ADMIN\ or if on Microsoft Windows HKEY_LOCAL_MACHINE > SOFTWARE > ORACLE > KEY_Ora_home > %ORACLE_HOME%\NETWORK\ADMIN\tnsnames.ora), will allow the file to be located and OCE to work.
Thanks for your update. Please try to run the report in Designer or Explore ( which you have installed in your desktop ). Confirm whether the bqy runs fine in your local desktop.
What is the Datasource you are using ( Oracle )
If Oracle is used, please check whether you are using Oracle net driver or ODBC driver.
if the Oracle net driver is used then check whether there is any upgrade happen on the server side with respect to oracle client software.
If the odbc driver is used check the ODBC connectivity on the odbc administrator window ( Start > Administrative Tools > Data source (ODBC)