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!
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.
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.
I just added the oracle folder to my environmental variables and that fixed my identical error
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
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://docs.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.
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
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.
Source: Stackoverflow.com