Oracle connection error on brand new server. But works on others. Unable to load OraOps12.dll


I have a fresh new Windows Server 2012r2 box. I have a tiny console .NET app that includes the native Oracle client dlls and tries to connect to an Oracle db and just execute a simple query. I have 4 other servers that can complete this test. This new machine cannot.

System.TypeInitializationException: The type initializer for 'Oracle.DataAccess.Client.OracleClientFactory' threw an exception. ---> System.DllNotFoundException: Unable to load DLL 'OraOps12.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

I tried to enable IIS on the server. no luck. I confirm the db is pingable from this server.

Not sure what else i can try or how else i can compare the machines that do work. None of these machines has ANY Obstacle software on them.

What else can i try?

asked on Stack Overflow Jan 4, 2017 by VBAHole

1 Answer


OraOps12.dll has a reference to the Visual C++ runtime (e.g. version 12.1 has a reference to the Visual C++ runtime 2013). When this runtime has not been installed on your server, the DLL cannot be loaded, and ODP.NET throws this exception.

A tool like Dependency Walker shows you to find missing DLL references and has saved me a lot of time to find missing dependencies on a new server.

answered on Stack Overflow Sep 11, 2017 by ppthetech

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