Windows – Connection to Oracle database via Visual Studio Server Explorer crashes Visual Studio

visual studio 2010windows 7

I am trying to create an ADO.Net entity Data Model of an existing oracle 11g database, however I cannot even get past the step of Database Connection.

Every time I attempt to test the connection Visual Studio closes without any details as to the error. Just this screen

Error Image

I am using following:

Visual Studio 2010 Ultimate

.NET 4.0.3

Oracle 11g client


Windows 7

Any help is appreciated. Thank you


This what I got from Event viewer of windows:

Faulting application name: devenv.exe, version: 10.0.40219.1, time stamp: 0x4d5f2a73

Faulting module name: oran11.dll, version:, time stamp: 0x4bb34692

Exception code: 0xc0000005

Fault offset: 0x0028deee

Faulting process id: 0x2020

Faulting application start time: 0x01cd5f6aa0a48f4f

Faulting application path: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe

Faulting module path: C:\app\User\product\11.2.0\client_2\bin\oran11.dll

Report Id: c2394ba8-cb5e-11e1-8347-005056c00008

Best Answer

This occurs when you install the ODAC into an existing Oracle Home.The OCI.DLL in your Oracle_Home was locked during the installation and was not overwritten.The OCI.DLL is now old and out of synch with the other DLLs, hence the crash.

The easiest solution is to simply reinstall into a new Oracle_Home (directory). If you must use the same Oracle_Home name and directory, you will still need to delete the now corrupted Oracle_home and then reinstall, using the following steps:

  • Use the installer to uninstall the entire oracle home that is crashing.
  • Look at the home in windows explorer. oci.dll should still be there.
  • Rename oci.dll to oci.toanything.
  • Reboot machine.
  • Go back to windows explorer and delete all remaining files in the oracle home, including oci.toanything.
  • Install ODAC.

Hope it helps.