Why does Oracle not find oci.dll?

Question

I use TOAD 10.2.1.3 under Windows7 and get the following error:

Cannot find OCI DLL: C:\Oracle\Product\11.2.0\oci.dll

that is strange because exact in the same path I can find oci.dll. That is 64 bit system, that might not be the problem! Any Idea? I am thankful for every hint!

Photometer

Is C:\Oracle\Product\11.2.0 part of your PATH environment variable? – Unbeaten

No but if I put it there it dose not work at all, really strange! I have no idea! – Photometer

@WernfriedDomscheit Just wanted to come say that, adding the path variable to the oracle folder fixed this error for me – Signora

I also faced this issue. Its because of missing/wrong value in your PATH variable. Once you validate restart the services for Oracle and instance, will solve this issue. – None

Answer 1

If you are using TOAD, you will need to download the 32-bit version of the Oracle Client Tools.

Since the Client Tools are different on a per-processor architecture basis, you probably need to install versions.

Statics

How can I know which version of Oracle Client Tools I have? – Photometer

You can check your registry. If Key HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_... exists then you have a 64bit Oracle Client installed. If Key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ORACLE\KEY_... exists then you have the 32 bit version. – Unbeaten

well, thanks to all of you, I have 64bit! I have just KEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_.. Now the question how can I change it please? – Photometer

In case you don't need the 64 bit client, you can de-install it and install the 32 bit client. In case you need both, follow this instruction: Stack Overflow - Install Oracle x86 and x64 – Unbeaten

@maniA: I would recommend to install both since the one program needs the 64-bit version and the other the 32-bit version. Just download the client tools from the Oracle website. – Statics

Answer 2

I notice that recent Oracle client installers change file permissions.

I had Oracle 12.0.1 32 bit client installed for a year. I recently installed Oracle 12.0.1 64 bit client. The Oracle install change ALL file permissions in the 32 bit folders.

My application suddenly failed to run.

I used PROCMON.EXE (https://learn.microsoft.com/en-us/sysinternals/downloads/) and noticed that permission was denied opening OCI.DLL

I changed the permissions for everything in the Oracle client folders and application works as expected.

Phonemics

faced the very same issue. is it documented anywhere? – Barna

Answer 3

I just installed Oracle Instant Client 18_3 with the SDK. The PATH and ENV variable is set as instructed on the install page but I get the OCl.dll not found error. I searched the entire drive recursively and no such DLL exists.

So now what?

With the install instructions (not updated for 18_3) and downloads there are MISTAKES at step 13, so watch out for that.

When you create the folder structure for the downloads just write them the old way "c:\oraclient". Then when you unzip the basic, SDK and instant Client install for Windows 10_x64 extract them to "C:\oraclient\", because they all write to the same default folder. Then, when you set the ENV variable (which is no longer ORACLE_HOME, but now is OCI_LIB64) and the PATH, you will point to "C:\oraclient\instantclient_18_3".

To be sure you got it all right drill down and look for any duplicate "instantclient_18_3" folders. If you do have those cut and paste the CONTENTS to the root folder "C:\oraclient\instantclient_18_3\" folder.

Whoever works on the documentation at Oracle needs to troubleshoot better. I've seen "C:\oreclient_dir_install", "c:\oracle", "c:\oreclient" and "c:\oraclient" all mentioned as install directories, all for Windows x64 installs

BTW, install the C++ redist it helps. The 18.3 Basic package requires the Microsoft Visual Studio 2013 Redistributable.

Brindisi

Answer 4

if you use 64-bit pc, oracle doesn't compatible with it. Oracle doesn't find oci.dll file in 64-bit.

Therefore, you can try to change oracle home on the top. As a result of that, home path will change.

At least, I solved that error with changing path.

Vial

Answer 5

I had this issue, I run 64 bit Windows and had downloaded the 64 bit TOAD package. I finally arrived at the conclusion that it was because I unzipped the package in a windows share using cygwin command line unzip. Turned out TOAD wasn't liking the permissions on some files. When I unzipped using windows File Explorer everything worked as expected.

Timeless

Answer 6

I just added the oracle folder to my environmental variables and that fixed my identical error

Signora

Answer 7

I was also looking for solving this issue. Maybe this answer will help someone.

In my case similar issue have appeared when I used Oracle Instant Client 18.5 for connecting to DB using Toad 13.1.1.5

To solve it I've downloaded more recent version of OIC - Oracle Instant Client 19.3 and Toad connected to Oracle's DB without issues.

Maybe there was version incompatibility issue. New version of Toad require a new version of oci library.

Both OICs were 64 bit and folders of both of them I've added into the user's Path variable.

Client OS: Win10

Server: OL7.7,

DB: 18c

Disappearance

Answer 8

I was using SQLTool where I was getting oci.dll was not found then I downloaded instantclient-basic-nt-12.2.0.1.0 extracted it and added the folder till oci.dll file in path variable

eg.: Path: .;D:\Softwares\Oracle Instant Client\instantclient_12_2

It resolve my issue, now I am able to open the SQLTool

Freely

Answer 9

Besides the many relevant and correct answers here, in my case I was also missing the "Microsoft Visual C++ 2010 Redistributable Package", which is needed by oci.dll and can be downloaded from microsoft.com.

Certificate

Answer 10

I had the same problem in windows 10 x64.

I downloaded oracle client version 21.7 for windows x64 from Oracle Offical Site.

I fixed the Oci.DLL problem by installing Microsoft Visual C++ Redistributable latest supported download for x64 from Microsoft Offical Site

Inartificial