"OCI_INVALID_HANDLE" or "Invalid Cursor" errors in Toad for Oracle and SQL Navigator. (4346793)

Toad for Oracle and SQL Navigator users receive an "OCI_INVALID_HANDLE" error when doing any of the following actions:

- Executing explain plan
- Opening SQL Editor window
- Opening Procedure Editor window
- Opening Schema Browser
- Connecting to the database

Using an unsupported Oracle Client version.

The Windows OS was upgraded, and the Oracle Client was not re-installed.

RESOLUTION 1:

Please use an Oracle client version that is supported by the Toad for Oracle version you are using.  Please see the Release Notes - System Requirements section.

RESOLUTION 2:

If the Windows OS was upgraded i.e. from XP to 7, re-install the Oracle Client as well.

Here are the Oracle download links for Oracle Client Software we recommend:

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32-bit Oracle 11g R2 Client – Download Link:

Oracle Database 11g Release 2 Client (11.2.0.1.0)
for Microsoft Windows (32-bit)
win32_11gR2_client.zip (684,581,290 bytes)

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win32soft-098987.html

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64-bit Oracle 11g R2 Client – Download Link:

Oracle Database 11g Release 2 Client (11.2.0.1.0) for Microsoft Windows (x64)
win64_11gR2_client.zip (615,698,264 bytes) (cksum - 2947608743)

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win64soft-094461.html

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ORACLE CLIENT SOFTWARE INSTALLATION NOTES:

- Ensure that your Windows User has Administrator Rights before installing an Oracle Client (or Toad).
- Toad for Oracle 11.5.1 and lower / SQL Navigator supports 32-bit Oracle Clients only.
- The above 32-bit client will work on a 64-bit Windows OS’s.
- During the Oracle Client installation, choose “Administrator” installation type (this is not automatically selected).
- Ensure you apply or copy over your TNSNAMES.ORA file (this file usually comes from your company). The default location for this file in 10g and 11g is:
10g - C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\
11g - C:\app\<YOUR_USER>\product\11.2.0\client_1\NETWORK\ADMIN\

NOTE: After installing the new client, ensure you select it in Toad’s / SQL Navigator’s login screen | under “Connect Using:” / “Oracle Home/Client:” (ensure you are NOT connected to any database for this setting to be available).

RESOLUTION 3:

Right-click the Toad for Oracle shortcut | Properties | Compatibility Tab | check mark "Run this program in compatibility mode for:" | choose "Windows XP Service Pack 3" or "Windows Vista Service Pack 2" from the drop-down list | click Apply and OK.  Re-test the issue.

RESOLUTION 4:

Right-click the ‘Toad for Oracle’ shortcut and select "Run as Administrator”. If this works, you can set it permanently via right-click the ‘Toad for Oracle’ shortcut | Properties | Compatibility Tab | check mark "Run this program as an administrator” | click Apply and OK.  Re-test the issue.

RESOLUTION 5:

Turn off UAC in Windows.

1) Go to Windows Start menu | under the Search field | type: UAC.
2) Move the slider bar to the lowest (disable notifications or never notify).
3) Restart the computer, and then re-test the issue.