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Connecting to Oracle from Within Visual Studio Fails With: ORA-12154 or ORA-6413, While Compiled Applications Run Fine (Doc ID 334968.1)

Last updated on JANUARY 30, 2022

Applies to:

Oracle Data Provider for .NET - Version and later
Oracle Net Services - Version to [Release 8.1.7 to 10.2]
Oracle Objects for OLE - Version to [Release 8.1.7 to 10.2]
Oracle ODBC Driver - Version to
Oracle Provider for OLE DB - Version to
Microsoft Windows x64 (64-bit)


You are developing an application inside Microsoft Visual Studio and receive one of the following errors when trying to connect to the Oracle database

     ORA-12154: TNS:could not resolve the connect identifier specified


     ORA-6413: Connection not open.


  • You can compile your application and then run the executable outside this location and it connects and executes successfully
  • You have installed 32-bit Oracle client software on a 64-bit Windows operating system (OS)


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