Toad connection Error:- "ORA-12154 TNS:could not resolve the connect identifier specified" or "ORA-06413: Connection not opened" or "Can't initialize OCI. Error -1" Solved

Tool for Oracle Application Development

Error connecting to database after installing on Windows 64-Bit OS

Problem Description

Any of the following errors can occur when attempting to connect to an Oracle database when installed on a Windows 64-Bit OS:

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

"ORA-06413: Connection not opened"

"Can't initialize OCI. Error -1"

Cause

This could be caused by an Oracle 10g client defect on Windows 64-bit. Oracle 11g is not affected. According to Oracle Metalink, Doc ID 334528, there is a network issue for any application that is installed into a path with a parenthesis using the 10g client on Windows 64-bit.

For example, C:\Program Files(x86)\Quest Software\

Resolution

RESOLUTION 1:

If you are running Oracle 10g please install your Quest application into 'C:\Quest Software' and not 'C:\Program Files (x86)\Quest Software.'

Note: If you are trying to install Toad into 'C:\Program Files\Quest Software', Windows will detect it as a 32-bit Program and install it back to 'C:\Program Files (x86)\Quest Software'

RESOLUTION 2:

If you want to keep your install into C:\Program Files (x86)\ Quest Software, then upgrade your client to Oracle 11g 32-bit as the issue is resolved there.

Note: Toad 10.1 to Toad 11.0.1 does support Windows 64-bit but the Oracle client still must be 32-bit.

source:https://support.quest.com/SolutionDetail.aspx?id=SOL12495

Even after you have done the above things sometimes you will get the below error on WINDOWS 7 & WINDOWS 8 64BIT Pcs.

"Can't initialize OCI. Error -1"

Then do the following things:

Right click on the Toad shortcut -> Go to -> Compatibility Mode -> check the box -> Run this program in compatibility mode for "Windows XP(Service Pack 3) & check the box -> Run this program as administrator.

In most cases problem will be Solved