All Oracle Error CodesOracle DBA Forum

PCC-02104:

Unable to connect to Oracle
Cause: The precompiler could not connect to Oracle with the username, password, and, if applicable, database link that was supplied. Note that this is a precompiler message, not a runtime message. This means that the USERID option value, either on the command line or in a configuration file, was incorrect.
Action: Check that the username and password are current and correct. Run SQL*DBA or SQL*PLUS and verify that connection can be made using that username and password.