Oracle Root keeps showing in Connect Using field and causes Ora-65535 error (4244295)

When trying to connect to a database an Ora-65535 error is being returned.  In the Connect Using dropdown, it shows Oracle Root as the client.  If the Connect Using value is changed from Oracle Root to the name of the actual Oracle client installed on the machine, then the database connects without issue.  However, if a second connection is attempted, the Connect Using field has Oracle Root listed again.  The second connection can be made without error.

If the databases are disconnected, so there are no more connections through Toad, when going back to the connection window, it still has Oracle Root listed in Connect Using.  If a connection is attempted, the Ora-65535 error is returned again.  When double clicking on the saved connection, it always has the Oracle Root saved as the client and always gives the error.  User has to manually change the Connect Using value to the actual client every time to get it to connect.

Open your registry, which you can do by typing regedit in the Windows start menu search field and click the regedit executable in the return results.  There are 2 nodes to check; HKLM\Software\Oracle and HKLM\Software\Wow6432Node\Oracle.

    

For each of those, Select the ORACLE node on the left and then look on the right.    If an ORACLE_HOME is listed, rename it to X_ORACLE_HOME or similar, then try Toad again.

Disclaimer : Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 "Description of the Microsoft Windows registry": http://support.microsoft.com/default.aspx?kbid=256986